stopped short of saying that Obama's birth certificate was real. The former Massachusetts governor was traveling to Las Vegas where he will be attending a fundraiser with Trump on Tuesday.

"You know, I don't agree with all the people who support me and my guess is they don't all agree with everything I believe in," the candidate explained.

"But I need to get 50.1 percent or more and I'm appreciative to have the help of a lot of good people."

Last week, Trump told The Daily Beast that Obama’s former literary agent had erroneously said the president was born in Kenya because it was the “truth.”

“He didn’t know he was running for president, so he told the truth,” the billionaire mogul insisted. “He said he was born in Kenya and raised in Indonesia… Now they’re saying it was a mistake. Just like his Kenyan grandmother said he was born in Kenya, and she pointed down the road to the hospital, and after people started screaming at her she said, ‘Oh, I mean Hawaii.’ Give me a break.”

Trump has also speculated that if Obama has a U.S. birth certificate then "maybe it says he is a Muslim."

Unlike Romney, former Republican presidential nominee John McCain often publicly confronted supporters when they made similarly outrageous comments.

At an October 2008 event in Minnesota, one women insisted that “Obama is an Arab.”

“No, ma’am,” McCain replied, drawing boos from the crowd. “He’s a decent family man [and] citizen that I just happen to have disagreements with on fundamental issues and that’s what this campaign’s all about.”

On Tuesday, the Obama campaign released a video noting, "As Republican nominee, John McCain stood up to the voices of extremism in his party."

"Why won't Mitt Romney do the same?" the video asks.

Romney’s senior adviser, Eric Fehrnstrom, on Friday defended the campaign’s ties to Trump.

“You know, not too long ago, Jay Carney, the spokesman for the White House made a statement which I think is correct, and that statement was that a candidate can’t be responsible for everything that their supporters say,” Fehrnstrom told CNN.

“And in this case, Mitt Romney has made it clear that the place of the president’s birth is not an issue for him. He accepts the fact that he was born in Hawaii. And we have many important challenges facing our country, and that’s what we’d rather talk about.”

Conservative columnist George Will on Sunday said that he did not understand why Romney was going forward with the Trump event.

“I do not understand the cost-benefit here,” Will told ABC’s Jake Tapper. “The costs are clear. The benefits – what voter is going to vote for him because he’s seen with Donald Trump? The cost of appearing with this bloviating ignoramus is obvious, it seems to me.”

“Donald Trump is redundant evidence that if your net worth is high enough, your IQ can be very low, and you can still intrude into American politics,” he added.