With only four days to go before South Carolina's Republican primary on Saturday, political mudslinging intensified Wednesday night among presidential candidates at the first of two GOP town halls.
At CNN's town hall, Sen. Marco Rubio, hours after receiving a key endorsement from South Carolina Gov. Nikki Haley, doubled down on his claim that Sen. Ted Cruz has lied about Rubio's record.
"If someone says something that's not true, and I don't clear it up, that's not fair," said Rubio, who said the back-and-forth with Cruz is "silly."
Meanwhile, Sen. Ted Cruz took the stage last and addressed a cease-and-desist letter that Donald Trump's campaign sent his campaign Wednesday demanding that he pull ads that use old footage of Trump talking about his previous pro-choice view. Trump says this is no longer his position.
"I'll confess I laughed out loud," Cruz said, reacting to the letter. "This letter pressed the bounds of the most frivolous and ridiculous letters I've ever seen."
Cruz told the voters at the town hall that Trump's policy positions don't make any sense and that his openness to the idea of impeaching President George W. Bush calls his judgment into question.
Rubio and Cruz both attacked President Obama's record, and each attempted to demonstrate that they have the policy chops to tackle a number of issues.
Reacting to news that Mr. Obama will travel to Cuba within the next month, both Rubio and Cruz said that they wouldn't travel to the Communist country until it's a free Cuba and no longer ruled by the Castro family.
Cruz continued to slam the president's foreign policy, calling it "hostile and antagonistic" toward Israel. He also laid out his plan to expand the U.S. military.
On comprehensive immigration reform, Rubio again tried to distance himself from the 2013 "Gang of Eight" immigration reform bill that he helped craft. He argued that "no progress" will be made on the issue until the U.S. secures the border first by building fences, a wall, improving the E-Verify system and deploying additional agents to the border.
Rubio touched on his proposals to help college students deal with debt and improve the economy through a plan to simplify the tax code. He argued he's qualified to be commander-in-chief after serving on the Senate Intelligence and Foreign Relations Committees in Congress.
On the new Defense Department's plan to allow women in combat, announced in December, Rubio said he's "open to both genders serving [in] the military," but that the U.S. shouldn't lower standards to serve. The Marines oppose allowing women into combat.
"For me, it's not about the gender; it's about the ability to do the job," he said.
Host Anderson Cooper asked candidates about news that the Obama administration is trying to get Apple to create new software so that it can access one of the San Bernardino attacks' phones.
Rubio said he doesn't have "a magic solution" to deal with the issue of encryption and tracking terrorists, but argued there has to be a process that would simultaneously protect Americans' privacy, but would also create a way for the government to crack these encrypted devices. Cruz said Apple should be compelled to search the device and that law enforcement has a strong argument to do so.
Ben Carson, who came in eighth place in last week's New Hampshire primary, kicked off the town hall who spent the first half hour arguing that his job as a neurosurgeon has prepared him well to be commander-in-chief because of the 2 a.m. phone calls he took and the "life or death" decisions he made.
He was asked if he were president today, would he nominate a person to succeed Supreme Court Justice Antonin Scalia who suddenly died last Saturday.
"I probably would take the opportunity to nominate someone," he said.
Carson also expressed confidence that he could defeat either Hillary Clinton or Sen. Bernie Sanders in a general election if he won the GOP presidential nomination.
"I would relish running against either one of them. It would not be a problem," he said.