CLEVELAND, Ohio — If Sen. Marco Rubio (R-FL) or former Florida Gov. Jeb Bush somehow win the Republican nomination despite their support of open borders immigration policies—and backing of full-scale amnesty for illegal aliens in America—billionaire businessman Donald Trump will not endorse them for president.

“Gentlemen, we know how much you love hand raising questions so we promise this is the only one tonight,” Fox News’ Bret Baier opened the debate by asking. “The only one. Is there anyone on stage—can I see hands—who is unwilling tonight to pledge your support to the eventual nominee of the Republican Party and pledge to not run an independent campaign against that person? Again, we’re looking for you to raise your hand now, raise your hand now if you won’t make that pledge tonight.”

Trump raised his hand.

“Mr. Trump. Mr. Trump, to be clear, you’re standing on a Republican—“ Baier started to follow up.

“I fully understand,” Trump said.

“The place where the RNC will give the nominee the nod,” Baier interrupted.

“I fully understand,” Trump said again.

“And the experts say an independent run would almost certainly hand the race over the Democrats and likely another Clinton. You can’t say tonight that you can make that pledge?” Baier followed up.

“I cannot say,” Trump responded. “I have to respect the person that if it’s not me, the person that wins. If I do win–and I’m leading by quite a bit–that’s what I want to do. I can totally make the pledge if I’m the nominee. I am discussing it with everybody. But I’m talking about a lot of leverage. We want to win and we will win. But I want to win as the Republican. I want to run as the Republican nominee.”

“Tonight you can’t say if another one of these—“ Baier started to follow up.

At that point, Sen. Rand Paul (R-KY) jumped in.

“This is what’s wrong. He buys and sells politicians of all stripes,” Paul said of Trump.

“He’s already hedging his bet, okay?” Paul added. “If he doesn’t run as an Republican, maybe he supports Clinton or maybe he runs as an independent. But I tell you, he’s already hedging his bets because he’s used to buying politicians.”

Trump then said he’s given Paul “plenty of money.”

“We’re going to move on. You’re not going to make the pledge tonight?” Baier followed up.

“I will not make the pledge at this time,” Trump replied.

Of course, Trump is wildly opposed to the candidacies of Bush and Rubio due to their positions on immigration. Rubio’s “Gang of Eight” amnesty bill last Congress—on which he worked with Democrats including likely future Majority Leader Sen. Chuck Schumer (D-NY)—would not have secured the border. Rubio still supports every policy in that bill, and the only position he’s changed since then is support for comprehensive immigration reform—he just now wants to do everything in the Schumer bill in a piecemeal fashion.

Bush supports virtually exactly the same policies as Rubio when it comes to immigration.