SCOTT SIMON: You say these tweets are, quote, "seemingly counterproductive." What's the seemingly part to you?

HANSON: Well, I mean, he is promoting an agenda on restoring legal immigration only and energy development, tax reform. That seems to poll pretty favorably with the American people. And yet the preponderance of a lot of his tweets are these ad hominem back and forth with individual media figures. And one would think that that would hurt those agendas, especially when there would be no need to get in these cul de sacs because there's public support for the agenda. But I say seemingly because every pundit who in the past has predicted that this was the road to perdition has been proven wrong.

SIMON: But let me ask you this. Whatever political effect - is it destroying civility in American politics?

HANSON: Trump is a catalyst. I think he's a symptom of the times. I mean, we've got to remember that way, way back, Jonathan Chait wrote an article about Bush, said, why I hate George Bush. Or Howard Dean said, I hate all Republicans. So Trump is a fish that swims in an existing lake. He didn't create Steve Colbert. He didn't create Bill Maher. He didn't create Kathy Griffin. He didn't create Madonna. All of that assassination chic was there before we got here.

SIMON: Well - but let me point out, professor Hanson, he's the president. He's not a late-night comedian. Shouldn't we expect more from the president?

HANSON: We should. But I think a lot of it involves nebulous questions of class and culture. And what I mean by that is what David Brooks said of Obama. He said, he talks like us. So if Obama jokes about using drones to kill potential suitors of his daughters, it's done in such a fashion that's not jolting.

But when you have somebody do it with dyed blond hair and orange tan and an outsized tie in a Queens accent and who's never had political and military experience, then we're not willing to give him the benefit of the doubt. There were past presidents who had said very divisive things - not maybe with the frequency as Trump. But they did so in such a way that was announced to be decorous and not subversive in the way that we look at Trump.