On Thursday, Bill Kristol joined MSNBC's Andrea Mitchell to talk about Republicans supporting Donald Trump.

"Trump is corrupting everyone who has supported him, or who is working for him, and even is accommodating or rationalizing," adding, if Pence "had his way, it would be a very different-looking campaign."

"But he can't just say, 'Look. I'm the vice presidential nominee, it would be better for the country if Donald Trump were president, here's why, policy policy policy.' Instead, he feels somehow compelled—I really don't understand this. Why does he have to say, 'I'm proud to stand with Donald Trump, shoulder to shoulder with Donald Trump. Donald Trump's a good man.' He's not proud to stand with Donald Trump."

Kristol added that Trump is "vulgarizing American politics," adding that Ryan ought to withdraw his support for Trump.

"But at some point, doesn't, sort of, self-respect sort of rear up and you just say to yourself why am I saying things I don't believe? Paul Ryan does not believe that Donald Trump should be the next president of the Untied States."

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