Trump challenged over claim that Bush lied about Iraq.

Donald Trump challenged over 9/11, Iraq War comments.

Donald Trump acknowledged Thursday that he "could have" signaled support for invading Iraq during a 2002 interview with Howard Stern.

"It was probably the first time I was asked that question," the GOP presidential front-runner told CNN's Anderson Cooper during a South Carolina town hall. "By the time the war started, I was against the war."

He also noted he "wasn't a politician" at the time of the interview.

Ahead of Saturday's South Carolina Republican primary, Trump has repeatedly blasted former President George W. Bush for launching the war.

But Buzzfeed posted Trump's interview with Stern earlier Thursday evening. When asked whether he would support an invasion, Trump responded: "Yeah, I guess so."

Trump's criticism of the war could be a risky move in this miliatry-dominated state. One man in the audience confronted Trump for saying that Bush had lied about the existence of weapons of mass destruction in Iraq.

Trump on Thursday was pressed several times -- both by the questioner and Cooper -- to clarify whether he believes or would again state that Bush had lied about the issue. Trump danced around the question, finally saying, "I don't know what he did."

"I would probably say that something was going on," Trump said. "I don't know why he went in" to Iraq.

Trump vs. Pope Francis

Trump called Pope Francis a "wonderful guy" after the pontiff said Thursday that the GOP presidential front-runner is "not Christian" if he wants to deport undocumented immigrants and build a wall along the U.S.-Mexico border.

"I don't think this is a fight," Trump said. "I think he said something much softer than was originally reported by the media."

Trump added he would meet with the Pope "anytime he wants."

Earlier at the town hall, Jeb Bush and John Kasich refused to be drawn into the debate between Trump and the Pope.

Kasich simply said he was "pro-Pope."

"This man has brought more sense of hope and more about the do's in life than the don'ts," Kasich said, referring to the Pope. "This guy has been so humble."

Bush, who is a devout Catholic, didn't criticize the Pope's comments. But he said he personally wouldn't "question people's Christianity."

"I think that's a relationship they have with their Lord and savior and themselves. So I just don't think it's appropriate to question Donald Trump's faith," Bush said. "He knows what his faith is."

Trump, who is dominating most South Carolina polls, continued to pound his closest competitor: Ted Cruz.

The billionaire businessman said the Texas senator "has a problem with the truth."

Trump appeared to side with Marco Rubio after the Florida senator's campaign accused Cruz's team earlier Thursday of photoshopping an image to make it appear as though Rubio is shaking hands with President Barack Obama.

"Oh, it was totally photoshopped," Trump said.

"They even made Marco a lot shorter than he is," Trump said, adding that this was "probably the thing that bothered him the most."

He quipped that other tactics the Cruz campaign has used in this election were "disgusting."

Trump has confounded many political observers with his propensity for colorful, unfiltered and inflammatory language as a candidate. When Cooper asked whether he would take on a different tone as president, Trump suggested he could easily switch back and forth between being politically correct -- and not.

"I can be more politically correct than anybody you've ever interviewed," Trump said.

He added: "I can do whatever I want. . . I deal with society. Society loves me."

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