Fact-checking the Republican presidential debate

As the first-in-the-nation Iowa caucuses near, the seven Republican candidates at Thursday's presidential debate in North Charleston, S.C., didn't need any help from the moderators to launch attacks at each other.

PolitiFact fact-checked several claims from the Fox Business Network debate, including a variety of candidate attacks about rivals' past stances and voting records. Here's a rundown.

Sen. Marco Rubio of Florida accused Texas Sen. Ted Cruz of flip-flopping on a laundry list of positions, including birthright citizenship.

"You used to say that you were in favor of birthright citizenship. Now you say that you are against it," Rubio said as Cruz vigorously shook his head.

While Cruz has shifted his talk about birthright citizenship, Rubio mischaracterized the way in which he switched.

The claim boils down to a 2011 radio interview on The Duke Machado Show during Cruz's first campaign for the Senate. The host asked Cruz whether the issue of birthright citizenship in the 14th Amendment should be changed. Cruz, a former prosecutor, said it would be difficult to revisit the provision because of the 14th Amendment.

"I've looked at the legal arguments against it, and I will tell you as a Supreme Court litigator, those arguments are not very good," he said. "As much as someone may dislike the policy of birthright citizenship, it's in the U.S. Constitution."

Pressed to clarify his view during the current presidential campaign, Cruz gave a series of interviews in August to show he opposed the practice.

He told Fox News' Megyn Kelly that birthright citizenship is an incentive for undocumented immigrants to come to America and that "we ought to change that policy" but that "there is a legal dispute about the best means to do it." He said "we should pursue" changing birthright citizenship through Congress or through a constitutional amendment, "whichever is effective."

Some conservative media outlets, and Rubio, have said this amounts to a "flip-flop" for Cruz. While he has now shifted in saying he wants to pursue a change of policy, that is different than what Rubio claimed.

We couldn't find any statements by Cruz that showed anything resembling support for birthright citizenship, and we don't read his resistance to fighting a constitutional amendment as support for the concept in the way his critics do.

That said, there has been a shift on one thing: Cruz now says he supports pursuing a change, either with an amendment or legislation. We rated Rubio's attack Mostly False.

Christie did support Sonia Sotomayor

Rubio, meanwhile, tried to highlight New Jersey Gov. Chris Christie's record, including the appointment of Supreme Court Justice Sonia Sotomayor. Rubio said Christie endorsed many of the ideas that President Barack Obama supports, "whether it is Common Core or gun control or the appointment of Sonia Sotomayor or the donation he made to Planned Parenthood."

Christie shot back, "Let's get the facts straight. First of all, I didn't support Sonia Sotomayor." He then continued to dispute the rest of Rubio's statement.

But that statement rates False. Christie did support Sotomayor by the end of the confirmation process.

When Sotomayor was nominated by Obama, Christie said in May 2009, "She wouldn't have been my choice, no." But two months later, Christie said that she had "more than proven her capability, competence and ability," adding, "I support her appointment to the Supreme Court and urge the Senate to keep politics out of the process and confirm her nomination."

Cruz right in back-and-forth with Rubio

Amid a heated exchange, Rubio attacked Cruz's record on defense spending.

"The only budget you have ever voted for, Ted, in your entire time in the Senate is a budget for (Sen.) Rand Paul that brags about how it cuts defense," Rubio said.

Cruz shook his head and said Rubio knowingly made an inaccurate claim.

"The attack he keeps throwing out on the military budget. Marco knows full well I voted for his amendment to increase military spending to $697 billion," Cruz said.

Cruz voted for a proposed Paul budget that would have resulted in lower defense spending than current projections — but he also voted for a Rubio amendment to increase military spending in March 2015 that was designed to counteract defense spending cuts. It failed 32-68.

We rated Cruz's counterpunch True.

Is Hillary Clinton under an FBI investigation?

The candidates also took aim at a leading Democratic candidate — Hillary Clinton. Former Florida Gov. Jeb Bush said Clinton might find herself preoccupied with an FBI investigation.

"She's under investigation with the FBI right now," Bush said. "If she gets elected, her first 100 days — instead of setting an agenda, she might be going back and forth between the White House and the courthouse."

Not quite. The FBI is conducting a general inquiry into the security of Clinton's private email server. But law enforcement officials have said Clinton herself is not the target of the inquiry, and it is not a full-blown criminal investigation.

Bush's claim rates Half True.

Wrong on refugees

Donald Trump repeated a false notion that the flow of Syrian refugees and other migrants consists largely of men.

"When I looked at the migration, when I looked at the line . . . where are the women?" Trump said. "There look like very few women. Very few children. Strong, powerful men. Young. And people are looking at that and saying, 'What's going on?' "

However, we found in October that the majority of more than 4.6 million Syrian refugees entering Europe are either women or children 17 and younger. Of migrants arriving by sea — about 1 million people — 31 percent are children and 19 percent are women. It was False then, and it's False now.

Aaron Sharockman, Lauren Carroll, Joshua Gillin, Amy Sherman, Katie Sanders and Angie Drobnic Holan contributed to this report. Read more debate rulings at PolitiFact.com.