8:11 p.m. In their closing statements, Jindal says he'll cut the size of government and cut government spending. Santorum says "working families is the key to us to win this election." Huckabee says he'll keep fighting for kids so they never forget where they came from. Christie said "the most disgraceful thing" he witnessed during the campaign so far was when Clinton joked that Republicans are her enemy.
7:53 p.m. Jindal said he would eliminate the federal corporate income tax entirely.
"We know big companies don't pay those big companies today," he said. "Make the CEOs pay the same rates as everybody else."
7:44 p.m. Christie said Democrats in Washington are "not standing behind our police officers across this country" and are "allowing lawlessness" in America.
"When President Christie is in the Oval Office, I'll have your back," he said.
7:41 p.m. Santorum dodged a question about whether he would support a federal gas tax hike and instead argued he's the most conservative candidate.
7:33 p.m. Fireworks are erupting between Christie and Jindal over their records. Jindal blasts Christie's increasing budgets in New Jersey while touting the budgets in Louisiana that he said he cut.
"Let's not be a second liberal party," Jindal said. "Let's not just beat Hillary. Let's elect a conservative to the White House, not just any Republican."
Christie said no one in New Jersey has ever called him a liberal.
Jindal then said to Christie, "I'll give you a ribbon for participation and a juice box."
7:29 p.m. Huckabee defends an earlier statement about how the U.S. shouldn't accept any Syrian refugees.
"We have no idea who these people are," he said. "Let's find out who they really are and who are really in danger...They don't know the language, the culture."
The former governor of Arkansas said the U.S. is $19 trillion in debt and must deal with homelessness first at home. He said he would support sending refugees food, but said "let's ask the Saudis to step up" instead of allowing the U.S. to do all the heavy lifting.
7:20 p.m. Again, Christie brings up Clinton.
"She is the real adversary tonight and we'd better stay focused as Republicans on her," he said. "Hillary Clinton is coming for your wallet everybody."
7:17 p.m. Jindal criticizes his rivals for claiming they've cut government spending in Washington when Jindal says they actually haven't.
"Here's a dirty little secret," he said, adding, "There's only one of us who actually cut government spending."
Huckabee shoots back saying Jindal's claim is inaccurate.
The governor of Louisiana said the GOP has been losing nationally because "we're trying to be cheaper versions of the Democratic Party."
7:12 p.m. Christie continues to hit Clinton.
"She believes she can make decisions for you better than you can make them for yourself," he said.
The New Jersey governor added, "get the government the hell out of the way and let the American people win once again."
7:05 p.m. First question is directed to Christie, who's asked what concrete steps he would take to get Americans back to work.
Christie slams President Obama for his economic policies and says Hillary Clinton would mean a continuation of them. He said he would make the tax code "fair, flatter, simpler" and get rid of special interest deductions.
"Everyone will get lower rates," he said, adding that people would be able to file their tax returns in 15 minutes. Christie also said he would "fire a whole bunch of IRS agents."
Huckabee said he would "get rid of the IRS" if he were president.
7:00 p.m. The second tier of candidates face off in the undercard debate on Fox Business Network and on wsj.com in Milwaukee, Wisconsin. They are Mike Huckabee, Chris Christie, Bobby Jindal and Rick Santorum.
Moderators are expected to ask candidates about the economy, jobs and taxes, as well as other domestic and international policy issues. Questions about Carson's personal history will likely be raised as he continues to defend his claims about his past.
Sen. Lindsey Graham of South Carolina and former New York Gov. George Pataki did not qualify for this debate.
The main Republican debate featuring the top eight candidates begins at 9 p.m. ET.