Charles Krauthammer said on "The O'Reilly Factor" tonight that he doesn't expect Donald Trump to sling insults at Thursday's Republican presidential debate.

Krauthammer said it's much more likely that a candidate who's not polling as well will go after Trump, which could provoke a reaction from the current GOP front-runner.

"So far, the game he's played is a winning hand," Krauthammer said. "Every time he gets attacked, it only strengthens him."

He added that Trump has proven he will be a durable candidate.

"The way he's survived, you have to say he's 'Teflon Don' up to now."

Watch the "Factor" discussion above.

Don't miss the Fox News-Facebook Republican presidential debate, Thursday August 6, live from Cleveland, Ohio at 9p ET, moderated by Megyn Kelly, Bret Baier and Chris Wallace. 

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