Most journalists stop short of calling Donald Trump a liar, even as they point out his many flip-flops and factual inaccuracies. Why? The Fix's Philip Bump answered this question comprehensively in the fall, but here's a good summary:

The problem that arises is that we can't know his intentionality. Unless Trump comes out and says something equivalent to, "I was trying to deceive people," we can't say with certainty that this was his intention — no matter how obvious it may seem and no matter how many times in the past we've wondered about his intentionality.

Enter Jimmy Kimmel, a late-night comedian bound by no such standards of prudence. While interviewing the presumptive Republican presidential nominee on ABC, Kimmel pointed out that Trump used to praise his likely Democratic rival, Hillary Clinton, whom he now trashes. Many reporters have done the exact same thing, but on Wednesday, Kimmel took it a step further, saying what they wouldn't and/or couldn't.

KIMMEL: In 2008 — I want to get this right — you said you thought Hillary would make an excellent president, and as recently as 2012 you said you thought she was terrific. What did she do? What happened?
TRUMP: Let me just explain to you. I will tell you, when I am a businessman — had a beautiful story recently where they said Trump is a world-class businessman — all over the world we're doing jobs. I speak well of everybody. If people ask me about politicians, I speak well. So when they ask me about Hillary, "She's wonderful," the husband — everybody's wonderful. And that's the way it is, including contributions. They ask me for contributions, I give contributions.
KIMMEL: So you were full of [it] when you said that.
TRUMP: A little bit. Maybe a little bit.

Kimmel, of course, didn't say "it." The word he said was bleeped, but you can probably guess what it was.

Plenty of people believed this all along, of course. And Trump is basically admitting as much when it comes to his past support of Democrats. He says he was nice to them and gave them money for his own personal gain — the implication being that his support wasn't genuine.

It was a laugh line, yes, but it was also a pretty telling moment.