More Democratic candidates jumped into the presidential race in 2019 than America has seen since the inception of the modern primary system. Here's a look at all the Democrats who campaigned for a chance to take on President Trump in November 2020.
O'Rourke was born and raised in the Texas border city of El Paso. The former congressman tried to topple Sen. Ted Cruz in 2018 and failed, but in the process shattered fundraising records and became one of the best known Democrats in the country.
At age 46, he's one of the younger contenders for the Democratic nomination.
The 67-year-old is perhaps best known for overseeing the legalization of marijuana in Denver while he was mayor and in Colorado as governor, although he opposed it.
The governor of Washington served two stints in Congress, a single term in the 1990s and then six Born and raised in Seattle, Inslee received a bachelor's degree in economics from the University of Washington in 1973 and a J.D. from Willamette University College of Law in Oregon three years later. After working in private law for more than a decade, he successfully ran for a seat in the Washington House of Representatives, where he served for four years until his successful bid for Congress in 1992. Inslee represented the state's 4th Congressional district for one term until his reelection bid was thwarted during the so-called Republican Revolution of 1994. During the following years, he unsuccessfully ran for governor and served as a regional Department of Health and Human Services (HHS) director under President Clinton. Inslee ran for Congress again in 1998 and defeated a Republican incumbent in Washington's 1st Congressional district, which he went on to represent for nearly 12 years. During his congressional tenure, the Washington lawmaker was a vocal critic of the war in Iraq and an early proponent of federal initiatives to reduce greenhouse gases and the American economy's reliance on fossil fuels.
Inslee left Congress in 2012 to launch his ultimately successful bid to be governor in Washington, defeating the state's Republican attorney general in the general election. After winning reelection in November 2016 -- the same time Mr. Trump unexpectedly won the presidency -- Inslee declared that "Washington was, is and will always be a beacon for progressive values." During his second term, Inslee has been a frequent cable news critic of the president and, with the help of the state's attorney general, Bob Ferguson, has challenged some of the Trump administration's policies, including the travel ban, through high-profile lawsuits.
In a campaign video focused on climate change, Inslee announced his White House bid on March 1.
Inslee will make climate change the top issue of his 2020 campaign, hoping to draw sharp contrasts with the environmental policies of Mr. Trump, who has repeatedly cast doubt on human-induced climate change, and even called it a Chinese hoax. He has been an ardent backer of sweeping federal action to mitigate the irreparable harm climate change is having on the global environment since his days in Congress. With most 2020 Democrats throwing their support for the audacious "Green New Deal" proposal introduced by New York Rep. Alexandria Ocasio-Cortez, Inslee's focus on climate change has the potential to gain traction among Democratic primary voters and prompt fellow contenders to discuss the issue even more during the nomination process.
Inslee is also likely on the campaign trail to tout the growing economy in his deep-blue state, his role in the passage of a net neutrality bill and what he called "the best paid family leave and one of the best minimum wages" in the country.
Inslee's tenures in Congress and as Washington's governor have largely been scandal-free.
However, some of his decisions as governor, including his backing of a controversial union legislation, have garnered opposition in Washington.
What Trump says
Mr. Trump has yet to tweet about Inslee or his presidential aspirations. In February 2018, however, the Washington governor confronted the president in the White House about his idea to arm teachers in the wake of multiple deadly school shootings.
"I just suggest we need a little less tweeting here and a little more listening. And let's just take that off the table and move forward," Inslee told the president during a meeting with other governors in the East Room.
Although he initially pushed back by saying he supported arming certain teachers, Mr. Trump listened with his arms crossed while Inslee pleaded for him to drop the idea and embrace other gun control measure
A senator and former congressman from Vermont, Sanders, a democratic socialist, came to prominence nationally when he ran for the Democratic presidential nomination in 2016. Although he ultimately lost to Hillary Clinton, Sanders developed a devoted following among younger Democrats despite being an independent.
At 78, Sanders is one of the oldest contenders for the Democratic nomination. A native of Brooklyn, he was mayor of Burlington, Vermont in the 1980s.
Amy Klobuchar was born in Plymouth, Minnesota, in 1960. Klobuchar has written about her troubled family life as a child in her book, "The Senator Next Door: A Memoir from the Heartland." Her father, Jim, was an alcoholic who frequently spent time away from family and was arrested for drunk driving. He and Klobuchar's mother, Rose, divorced when Klobuchar was 15. The divorce took a toll on her family, causing her younger sister, Beth, to drop out of high school. Although Klobuchar's parents reconciled a few years later, she has written that her relationship with her father was not repaired until he quit drinking in the 1990s.
Klobuchar attended Yale University and University of Chicago Law School. She returned to Minnesota after graduating and worked for a private law firm. Her experience of being forced to return to work one day after giving birth inspired her to become politically active and advocate for a maternity leave bill in the state legislature. Klobuchar was elected Hennepin County attorney in 1998. She was first elected to the Senate in 2006, and won re-election in 2012 and 2018. Klobuchar and her husband, John Bessler, have one daughter. Bessler is a private practice attorney and a professor at the University of Baltimore School of Law.
The three-term Minnesota senator launched her presidential campaign on Feb. 10 under frigid temperatures and relentless snowfall in Minneapolis.
Klobuchar is a very active senator who is often willing to work on a bipartisan basis. As of December, Klobuchar has sponsored 111 pieces of legislation which have been signed into law. However, Klobuchar is also ideologically liberal on several issues.
As a member of the Senate in 2009, Klobuchar voted to pass the Affordable Care Act, commonly known as Obamacare. She is pro-choice and supports LGBT rights. She also has an "F" rating from the National Rifle Association.
Klobuchar is a member of the Senate Judiciary Committee, and made a name for herself in 2018 for her calm yet incisive questioning of then-Supreme Court nominee Brett Kavanaugh during the hearings investigating claims of sexual misconduct against Kavanaugh in September. At one point, when asking if Kavanaugh had ever blacked out from drinking, he retorted: "Have you?" The moment quickly went viral, and Kavanaugh later apologized.
Klobuchar was the sole senator from Minnesota during the resolution of the contested Senate election from January to July 2009, which Al Franken eventually won. When Franken was accused of sexual harassment in December 2017, Klobuchar did not call for Franken to step down, unlike many other senators. Franken resigned shortly after the allegations came to light.
"I felt I was in a different role as his colleague, that I'm someone that has worked with him for a long time, there's a lot of trust there, and I felt it was best to handle it in that way," Klobuchar told CNN at the time about why she did not call on him to resign.
What Trump says
A few hours after her announcement, President Trump mocked Klobuchar for discussing efforts to mitigate climate change during a Midwestern snowstorm. "Amy Klobuchar announced that she is running for President, talking proudly of fighting global warming while standing in a virtual blizzard of snow, ice and freezing temperatures. Bad timing. By the end of her speech she looked like a Snowman(woman)!" the president tweeted.
Cory Booker was born in Washington in 1964 and raised in the affluent suburbs of northern New Jersey. He received a bachelor's degree in political science and a master's degree in sociology from Stanford University, where he also played tight end for the football team. After graduation, Booker was awarded a Rhodes scholarship to study at the University of Oxford, earning a master's degree in modern history. He returned to the U.S. for a law degree at Yale.
After working as a public-interest attorney and housing advocate in Newark, Booker decided to run for the city's municipal council in 1998. He managed to topple a long-time incumbent and, at age 29, become the youngest-ever member of the council, where he gained notoriety for fasting outside a housing project to denounce the intensifying crime and drug use in some of Newark's neighborhoods. After launching an unsuccessful bid in 2002 against incumbent mayor Sharpe James, Booker ran again in 2006 and defeated deputy mayor Ronald Rice. During his seven-year tenure as mayor, Booker was praised for attracting large companies to Newark and revamping the city's downtown. But he was also criticized by local residents and officials for appearing out-of-touch and focusing on his national image. "The only way you can see the mayor is if you turn on 'Meet the Press,'" Newark's current mayor, Ras Baraka, said when he was a councilman during Booker's mayoral administration.
After longtime New Jersey Senator Frank Lautenberg died in the summer of 2013, Booker ran to fill his seat and defeated a little-known Republican mayor in a special election. In 2014, he won reelection to serve a full term in the Senate. During his years in the Senate, he has sought to promote bipartisanship through conciliatory rhetoric.
Booker announced he was running for president on Feb. 1, 2019, the first day of Black History Month.
He has made criminal justice reform and the decriminalization of marijuana integral issues of his agenda in the Senate. Pointing to the disproportionate incarceration of minorities for marijuana-related offenses, he crafted the Marijuana Justice Act in the summer of 2017. The bill would remove marijuana from the 1970 Controlled Substances Act, withhold federal funding for states which continue to criminalize the substance, require courts to expunge convictions for marijuana use or possession and establish a federal fund to help low-income communities affected by the so-called "war on drugs."
The junior senator from New Jersey is one of the chief architects of the First Step Act, a landmark bill that President Trump signed into law in December after rare overwhelming bipartisan support in Congress. The legislation increases investment in programs to curb recidivism among federal prisoners and modifies several sentencing laws, including mandatory minimum sentences for nonviolent drug offenders. Although he hopes to tout it as a signature achievement of his career in Congress, Booker acknowledged that the bill is just one stepping stone to overhaul the criminal justice system.
Although he has a liberal voting record in the Senate and has been a staunch critic of the Trump administration, Booker has faced criticism from some progressives for receiving large donations from pharmaceutical corporations and banks.
In what he touted as his "Spartacus" moment, Booker claimed to have released confidential committee documents during the contentious Senate confirmation of Justice Brett Kavanaugh. His Republican colleagues accused him of grandstanding and said the documents had already been cleared.
What Trump says
In an exclusive interview with CBS News "Face the Nation" host Margaret Brennan the same day Booker announced his candidacy, President Trump said he thinks Booker has "no chance" in the 2020 election.
When asked why, Mr. Trump replied: "Because I know him. He has no chance."
In a November interview with the New York Post, the president said Booker "ran Newark into the ground" and falsely accused him of not living in the city when he was mayor.
During the 2016 campaign, Mr. Trump claimed to know more about Booker than the New Jersey senator knew about himself. "If Cory Booker is the future of the Democratic Party, they have no future! I know more about Cory than he knows about himself," Mr. Trump tweeted in July of that year.
The youngest of the presidential contenders, Pete Buttigieg is also the only openly gay candidate who has jumped into the race. Buttigieg, 37, ran for mayor of South Bend, Indiana, his hometown, when he was only 29. He is a graduate of Harvard and was a Rhodes Scholar at Oxford University.
After becoming mayor in 2011, Buttigieg deployed to Afghanistan for a seven-month tour in 2013 as a member of the Navy Reserve. In 2015, shortly before the Supreme Court decision legalizing same-sex marriage, Buttigieg came out as gay in an essay in the South Bend Tribune, becoming the first openly gay municipal leader in Indiana. If nominated, Buttigieg would be the first openly gay presidential nominee.
Buttigieg ran for chairman of the Democratic National Committee in 2017, running as a dark horse candidate with the backing of former DNC Chairman Howard Dean. However, Buttigieg withdrew from the race on the day of the election, acknowledging his long-shot candidacy.
Buttigieg married his husband, Chasten Glezman, in June 2018.
Buttigieg has spent much of his time as mayor of South Bend focusing on redevelopment and construction, such as implementing a project to repair or demolish targeted properties across the city and adding pedestrian and bike-friendly amenities to city streets.
Buttigieg is making the case that South Bend's economic struggles are a microcosm of the problems the country is experiencing. The city saw a declining population due to the loss of factory jobs, but it has increased since Buttigieg took office. He has focused on improving higher education and health care in the city.
In the video announcing his exploratory committee, Buttigieg emphasizes the need for a "fresh start" in American politics. He also discusses the issues important to him as a member of the millennial generation, saying: "We're the generation that lived through school shootings, that served in the wars after 9/11, and we're the generation that stands to be the first to make less than our parents. Unless we do something different."
Buttigieg has very little controversy around him, other than his age and sexual orientation, which some consider to be automatic strikes against him.
In his first term as mayor, he dealt with a scandal at the local police department, which led him to demote the first African American chief of police of South Bend.
What Trump says
President Trump has not tweeted about or insulted Buttigieg as of now.
Harris was born in Oakland in 1964 and raised in a multicultural household. Her mother, Shyamala Gopalan Harris, was a scientist from India and her father, Donald Harris, an economics professor at Stanford University, was born in Jamaica. Harris went to high school in Canada, where her mother worked as a hospital researcher and college professor. She returned to the U.S. to go to college at Howard University, a historically black university in Washington, D.C. and then went on to attend law school at the University of California, Hastings.
Upon graduation, Harris stayed in the Golden State and worked for the Alameda County district attorney's office in Oakland. In 2003, she was elected San Francisco district attorney, a position that had never been held by a woman or person of color. During her 10-year tenure as the city's chief law enforcement officer, Harris spearheaded efforts to curb high recidivism rates among released prisoners and created a nationally recognized reentry program for nonviolent, first-time drug offenders. After winning a hotly contested race in 2010, Harris became California's first female attorney general, as well as the first Indian-American and Jamaican-American to hold the post. During her two terms, Harris' office implemented implicit bias training among officers and defended several state lawyers dogged by accusations of prosecutorial misconduct.
After Sen. Barbara Boxer announced her retirement, Harris launched a bid for her seat. In 2016, she defeated Rep. Loretta Sanchez, also a Democrat, in a landslide and became the first woman of color to represent California in the Senate. During her two years on Capitol Hill, Harris has solidified herself as a leading critic of the Trump administration, known for her fierce questioning as a member of the Judiciary and Homeland Security and Governmental Affairs committees. Harris announced her presidential candidacy on Martin Luther King Jr. Day, Jan. 21, 2019.
In her short tenure in the Senate, Harris has compiled a liberal voting record and has overwhelmingly voted against President Trump's nominees for cabinet-level and other administration positions. Along with her tough, prosecutorial cross examinations during committee sessions, Harris has advocated for criminal justice and immigration reform and has contrasted her platform with Mr. Trump's agenda.
Although she opposed the legalization of recreational marijuana during her law enforcement career in California, Harris announced her support for the Marijuana Justice Act crafted by Sen. Cory Booker, D-New Jersey. The bill would remove marijuana from the 1970 Controlled Substances Act, withhold federal funding for states which continue to criminalize the substance, require courts to expunge convictions for marijuana use or possession and establish a federal fund to help low-income communities affected by the so-called "war on drugs."
In October, Harris unveiled new tax legislation aimed at the middle class to give families up to $6,000 a year in refundable tax credits, which she will likely highlight on the 2020 campaign trail.
Although she is likely to cite her long career as a prosecutor on the campaign trail, Harris is poised to face scrutiny from some progressives for her law enforcement work. Some factions on the left have denounced aspects of her record as a district attorney and state attorney general. Critics have pointed to California's overcrowded prisons and to her defense of controversial convictions to challenge the notion that she was a "progressive prosecutor."
"If Kamala Harris wants people who care about dismantling mass incarceration and correcting miscarriages of justice to vote for her, she needs to radically break with her past," wrote law professor Lara Bazelon in an opinion piece for The New York Times.
What Trump says
Although Mr. Trump has not yet tweeted about Harris, the White House has previously criticized the California senator. In the summer of 2018, the White House Twitter account wrote, "@SenKamalaHarris, why are you supporting the animals of MS-13? You must not really know what ICE does." Harris has said that lawmakers need to "reexamine" the role of Immigration and Customs Enforcement (ICE).
Warren was born in 1949 and raised in Oklahoma, where her father worked as a janitor and her mother took a minimum wage job at Sears. She has described growing up "in a paycheck-to-paycheck family" that lived "on the ragged edge of the middle class." Warren first married at age 19 and became an elementary school teacher after graduating from the University of Houston. She began law school at Rutgers University when her daughter was two years old, and she gave birth to a son soon after earning her degree. Warren served as a law professor for three decades, and spent 20 of those years at Harvard Law School. Massachusetts Rep. Joe Kennedy III and Arkansas Sen. Tom Cotton were among her students there.
After the 2008 financial collapse, Warren was tapped to lead the congressional oversight panel for the Troubled Asset Relief Program, known as TARP. She served as the architect of the Consumer Financial Protection Bureau under the 2010 financial reform law known as Dodd-Frank. In those roles, she became a prominent figure on the national stage and a hero among progressive populists. But her views on the economy garnered plenty of critics within the Republican Party and among Wall Street bankers. Such opposition derailed Obama administration plans to nominate her to officially run the CFPB. Instead, she ran for the U.S. Senate in 2012 and defeated incumbent Massachusetts Republican Sen. Scott Brown--her first run at public office. Warren was re-elected in 2018, and announced an exploratory committee for a presidential run Dec. 31.
Warren and her second husband, Bruce Mann, have been married for 38 years and have three grandchildren. They live in Cambridge, Massachusetts with their golden retriever, Bailey, who came to her first press conference as a presidential contender.
Warren has built a national brand as an economic populist and an anti-Wall Street crusader. The 69-year-old senator serves on the Senate Committee on Banking, Housing, and Urban Affairs Committee and the Health, Education, Labor, and Pensions Committee in the Senate, and has also taken on her own party on issues she cares about. In one instance, she helped to derail then-President Obama's nomination of investment banker Antonio Weiss to a top position at the Treasury Department in 2015.
Fixing a "rigged" economy figures to be central issue of her presidential campaign. "I've spent my career getting to the bottom of why America's promise works for some families, but others who work just as hard slip through the cracks into disaster," Warren said in a video announcing her presidential exploratory committee. "What I found is terrifying. These aren't cracks that families are falling into. They're traps. America's middle class is under attack. How do we get here? Billionaires and big corporations decided they wanted more of the pie and they enlisted politicians to cut them a fatter slice."
During a press conference after announcing her exploratory committee, Warren pushed for more accountability in the economy and pledged to go after drug companies. "The problem is Washington works great for those with influence." Warren also came out against political action committees to fund campaigns. "Democrats are the party of the people -- we join together and we fund our campaigns," she told reporters. "We make our campaigns work through the people."
Warren's claims of Native American ancestry, which her opponents say she used unfairly to get ahead, have been the source of controversy since her first run for the Senate. In an attempt to silence critics --namely, President Trump -- ahead of a presidential bid, Warren released the results of a DNA test in 2018 that showed a tiny portion of Native American heritage, along with a campaign-like video about her family history. The move backfired, inviting criticism from tribal leaders and Native American groups. And it raised questions about how effectively Warren will be able to compete with President Trump.
What Trump says
The heritage controversy put Warren high on Mr. Trump's hit list. He frequently refers to her as "Pocahontas," and while campaigning over the summer, he pledged to give $1 million to charity if she would take a DNA test. He later denied making the pledge once she released the results of the test but has continued to criticize Warren over the backlash to her DNA video.
"She did very badly in proving that she was of Indian heritage. That didn't work out too well," Trump told Fox News in an interview on New Year's Eve. "We'll see how she does. I wish her well, I hope she does well. I'd love to run against her."
Warren frequently taunted Mr. Trump during the 2016 campaign, and often takes to the president's favorite outlet, Twitter, to criticize him and his policies directly. Asked by Fox News whether Warren would be able to win, the president said, "Well, that I don't know. You would have to ask her psychiatrist."
Kirsten Gillibrand, born in 1966, is not the first woman in her family to become involved in politics. Her grandmother, Polly Noonan, was the founder of the influential Albany Democratic Club and was a major player in Albany Mayor Erastus Corning's political machine. Gillibrand, the daughter of two attorneys, was raised in Albany. She attended Dartmouth University and UCLA School of Law.
Gillibrand worked at the private Manhattan-based law firm Davis Polk in the early 1990s, although she took a brief leave in 1992 to serve as a law clerk to Circuit Court Judge Roger Miner, a Ronald Reagan appointee. She served as special counsel to then-HUD Secretary Andrew Cuomo in the final year of the Clinton administration. She was a strong supporter of Hillary Clinton, and worked on her 2000 Senate campaign. Clinton became a mentor to Gillibrand, and encouraged Gillibrand to run for office in 2006 rather than in 2004, believing that running two years later would give her a greater chance of winning.
Gillibrand defeated four-term Rep. John Sweeney, who represented a conservative district, in 2006. Gillibrand was a moderate congresswoman and a member of the conservative Democrat Blue Dog Caucus. She supported a bill to withhold funds from sanctuary cities, and received a 100 percent rating from the National Rifle Association. After Clinton left the Senate in 2009 to become secretary of state, Gov. David Paterson appointed Gillibrand to replace her.
Gillibrand's positions have become more progressive during her time in the Senate.
Gillibrand advocated the repeal of the "Don't ask, don't tell" policy on LGBT military service when she got to the Senate in 2009. She made a name for herself in the Senate by addressing sexual assault in the military. She proposed legislation that would remove sexual assault cases from the military chain of command in 2013, legislation which was co-sponsored by Republican Senators Rand Paul and Ted Cruz. Although the legislation failed, it raised her profile as an advocate for women.
Gillibrand has acknowledged her changed positions on immigration and gun control, saying in a "60 Minutes" profile in 2018 that she was "embarrassed and ashamed" of her stances while serving in the House.
Health care has been an important issue for Gillibrand since entering the Senate. She came out in favor of single-payer healthcare in 2017 and co-sponsored a Medicare-for-all bill introduced by Sen. Bernie Sanders. She was the first sitting senator to call for U.S. Immigration and Customs Enforcement to be abolished, a popular cause on the left.
Gillibrand has faced criticism for representing cigarette manufacturer Philip Morris during her time at Davis Polk, including in civil and criminal investigations by the Department of Justice. She has also been accused of political opportunism for changing her positions so dramatically when she entered the Senate.
The New York senator has alienated some in her party with her hardline position on responding to sexual misconduct. She was the first senator to call on Sen. Al Franken to resign in 2017 after he was accused of sexual harassment by several women. A few big Democratic donors, including billionaire George Soros, have said that they will not support Gillibrand because of her position on Franken.
She has also distanced herself from the Clintons. In November 2017, she said that President Bill Clinton should have resigned after his affair with White House intern Monica Lewinsky became public.
What Trump says
President Trump tweeted at Gillibrand in December 2017 after she called on the president to resign due to sexual misconduct allegations against him.
"Lightweight Senator Kirsten Gillibrand, a total flunky for Chuck Schumer and someone who would come to my office "begging" for campaign contributions not so long ago (and would do anything for them), is now in the ring fighting against Trump. Very disloyal to Bill & Crooked-USED!" Mr. Trump tweeted. Critics interpreted the words "begging" and "used" in the tweet as having a sexual connotation.
"You cannot silence me or the millions of women who have gotten off the sidelines to speak out about the unfitness and shame you have brought to the Oval Office," Gillibrand wrote on Twitter in response.
Julián Castro was born one minute before his identical twin brother, Joaquin, in San Antonio, Texas, in 1974. His mother, Maria, was a Chicana political activist whom Castro has credited for motivating him and his brother to choose careers in public service. Joaquin Castro is currently a congressman.
Castro attended Stanford University and Harvard Law School, along with his brother. He was elected to the San Antonio City Council in 2001 at the age of 26, making him the youngest council member in San Antonio history. He unsuccessfully ran for mayor in 2005, but won when he ran again in 2009. He was re-elected twice, in 2011 and 2013. Castro's profile rose when he was chosen to give the keynote speech at the 2012 Democratic National Convention, the first Hispanic person to do so.
In 2014, President Obama named Castro Housing and Urban Development secretary. During the 2016 election, he was among those considered a possible vice presidential nominee for Hillary Clinton, although Clinton eventually chose Virginia Sen. Tim Kaine.
Castro laid the groundwork for a 2020 presidential bid throughout 2018, visiting New Hampshire and publishing a memoir, "An Unlikely Journey: Waking Up from My American Dream," in October. He announced the creation of an exploratory committee for a presidential run Dec. 12 and officially announced his candidacy for president Jan. 12.
Castro and his wife, Erica, have two children.
Castro's tenure at HUD was marked by a focus on fair housing issues. In his exit memo from the agency, Castro said that HUD had stabilized the housing market and preserved affordable housing through public-private partnerships. Under the Obama administration, he wrote, HUD invested $18 billion in communities recovering from natural disasters and initiated a "$1 billion competition for resilient housing and infrastructure projects."
Views on LGBT issues and abortion rights
He supports LGBT rights and was the first San Antonio mayor to serve as the grand marshal of the city's Pride Parade in 2009 and joined mayors across the country in signing the "Mayors for the Freedom to Marry" petition for same-sex marriage equality in 2012.
Castro is also a supporter of the rights of women to have an abortion. He spoke at the annual luncheon for Planned Parenthood South Texas in May.
In 2016, the Office of the Special Counsel, an independent federal investigative body, found that Castro had violated the Hatch Act by commenting on the 2016 presidential campaign during an interview about local issues. Castro apologized and ordered his team improve training on the Hatch Act in his department.
What Trump says
Castro has not yet been a target for President Trump. Unlike some of the other potential presidential candidates, Mr. Trump has never personally disparaged Castro on Twitter.
In his video announcing his exploratory committee in December, Castro said he is focused on affordable college, care for seniors, universal health care and welcoming immigrants.
"No matter where we're from, we're united by the same daily needs -- a good job, a good education for our kids, good health care, an affordable place to live. The need to be acknowledged for our contributions, not for our gender or who we love. We all hope our children have clean air to breathe and clean water to drink. We all hope they can worry about their studies, not their safety," Castro said.
Tulsi Gabbard was born in American Samoa in 1981, and her family moved to Hawaii when she was 2 years old. Her mother, Carol, is a practicing Hindu, a religion Gabbard adopted. Her father, Mike, is a member of the Hawaii state Senate.
After growing up in a politically active family, Gabbard became a member of the Hawaii House of Representatives when she was 21 years old in 2002, the youngest woman to be elected to a state legislature at the time. While serving in the state legislature in 2003, she enlisted in the Hawaii Army National Guard. She deployed in Iraq and returned in 2006.
After returning from her second deployment in 2009, Gabbard ran for Honolulu City Council. She served on the council from 2011 until 2012, when she resigned to focus on her congressional campaign. She was elected to the House of Representatives in 2012. She was the first practicing Hindu in Congress.
Gabbard is very progressive, and one of the few members of Congress to endorse Sen. Bernie Sanders during the 2016 Democratic primary. She resigned her position as vice chair of the Democratic National Committee to endorse him.
Gabbard is a supporter of a woman's right to an abortion and received a 100 percent rating from NARAL. She has emphasized environmental and economic issues during her tenure, and supports a $15 minimum wage. She also supports Medicare for All.
Although she began her career opposing LGBTQ rights, she is now a supporter of LGBTQ issues and has apologized for her previous views.
Gabbard's father was an anti-gay activist whose views influenced his daughter during her early political career. When she ran for the Hawaii state legislature in 2002, Gabbard boasted about supporting her father in his effort to promote the constitutional amendment banning same-sex marriage passed in 1998. After her election, she continued to espouse anti-gay views. In 2004, she opposed a bill legalizing civil unions.
"To try to act as if there is a difference between 'civil unions' and same-sex marriage is dishonest, cowardly and extremely disrespectful to the people of Hawaii," Gabbard said at the time, according to CNN's KFile. "As Democrats we should be representing the views of the people, not a small number of homosexual extremists."
Gabbard apologized to LGBTQ activists in the state when running for Congress in 2012. She apologized again after launching her presidential campaign.
Gabbard has invited controversy for her iconoclastic views on foreign policy. In January 2017, she visited Syria and met with Syrian dictator Bashar al-Assad. A few months later, the U.S. bombed the Syrian airfield thought to be the origin of a government-ordered deadly chemical attack. Gabbard called the U.S. bombing reckless and questioned whether Assad was behind the attack, garnering criticism from other Democratic politicians.
In November, she said in a tweet that President Trump is "Saudi Arabia's bitch" for announcing the U.S. will stand with Saudi Arabia, regardless of any intelligence community assessment on Saudi Crown Prince Mohammed bin Salman's involvement in the killing of Washington Post columnist Jamal Khashoggi.
What Trump says
Mr. Trump has not publicly criticized Gabbard. The two met briefly shortly after Mr. Trump was elected.
The little-known former congressman from Maryland was the first to announce his candidacy for president, declaring in July 2017. Delaney, 55, was raised in New Jersey and attended Columbia University and Georgetown University Law Center.
Delaney co-founded two profitable companies, both of which are publicly traded on the New York Stock Exchange. He was elected to Congress in 2012, and served three terms in the House of Representatives.
Biden was born in Scranton, a city in northeastern Pennsylvania, in late 1942, when the U.S. was fighting the Axis powers in World War II. In the 1950s, his family moved to Delaware, where he attended a private Catholic academy and eventually, the University of Delaware for his bachelor's degree in political science and history. After earning his law degree from Syracuse University in 1968, Biden worked for several law firms before being elected to a seat in the New Castle County Council.
After only a few years in that post, Biden decided to launch an underdog campaign for one of Delaware's Senate seats in 1972. Despite having little experience, he beat Sen. Caleb Boggs, a 12-year incumbent, in the general election.
His surprising victory, however, was overshadowed by tragedy. Biden lost his first wife, Neilla Hunter, and one-year-old daughter, Naomi, to a car accident days before Christmas in 1972. His sons, Beau and Hunter, were badly injured but survived. The grief reportedly prompted Biden to reconsider joining the Senate, but he decided to assume the position. At age 30, he was sworn in as one of the youngest U.S. senators in 1973 at the Wilmington Medical Center, where Beau was still recovering from his injuries.
During his long tenure in Congress, Biden solidified himself as one of the most influential members of the Senate, leading two of its most powerful panels, the Judiciary and Foreign Affairs Committees, during different terms. He was considered a centrist Democrat who was willing to hash out bipartisan deals with Republicans.
During his time in Congress, Biden remarried and commuted to Washington, D.C. from his home in Delaware via Amtrak -- so he could see his sons every night after they lost their mother and sister.
Biden also sought the Democratic presidential nomination in 1988 and 2008, dropping out during the primary in both. The one in 1988 was derailed by a plagiarism scandal while in 2008, he failed to gain much traction in the primary and made several gaffes on the campaign trail. After Biden dropped out of the 2008 race, Mr. Obama, at the time the Democratic Party's nominee, picked the Delaware senator to be his running mate.
After Mr. Obama's historic election, Biden resigned from the Senate to be sworn in as America's 47th vice president in 2009.
In the 1970s, Biden opposed busing to desegregate public schools. As chairman of the Senate Judiciary Committee, he oversaw the contentious Anita Hill hearings during the confirmation process for then-Supreme Court nominee Clarence Thomas in 1991. Progressives have denounced his handling of the hearing, alleging he did not do enough to empower Hill's testimony. Biden also helped spearhead efforts to pass the Violent Crime Control and Law Enforcement Act of 1994 that many believe fueled a period of mass incarceration that disproportionately affected African-Americans and other minority groups.
Separately, Biden has come under scrutiny in recent weeks by several women who said he touched them inappropriately at events over the years. In a video earlier this month, he pledged to be more respectful of personal spaces, but stopped short of offering a full apology.
What Trump says
Biden was sharply critical of then-candidate Donald Trump on the 2016 campaign trail, where he stumped for Hillary Clinton. During Mr. Trump's time in the White House, the former vice president has consistently spoken out against the administration's policies and rhetoric. Last year, he told a crowd he would've "beat the hell out" of Mr. Trump because of his remarks about women if the two had been in high school together. The president responded by accusing Biden of trying to be a "tough guy."
Since reports have surfaced bout Biden joining the 2020 race to challenge him, the president has called the former vice president a "sleepy" and non-threatening potential general election opponent
"I don't see Joe Biden as a threat," Mr. Trump told reporters earlier this month.