Susan Glasser writes this for The New Yorker, under the headline "It’s True: Trump Is Lying More, and He’s Doing It on Purpose":
On Thursday, the Washington Post published a remarkable story on its front page revealing a recent spike in the number of “false and misleading claims” made by President Trump. In his first year as President, Trump made 2,140 false claims, according to the Post. In just the last six months, he has nearly doubled that total to 4,229....
History books will likely declare the last few months a turning point in the Trump Presidency.... The upsurge provides empirical evidence that Trump, in recent months, has felt more confident running his White House as he pleases, keeping his own counsel, and saying and doing what he wants when he wants to.
I think it's more than that. The specific content of most of Trump lies makes him seem, to his base, as if he's even more of a demigod (and a martyr) than they thought he was -- but there's also value for him in lying just for the sake of lying. When he lies, mainstream media fact checkers call him out for it. That alone is a plus for him. He's admired even more by his fan base every time he's called out by "the fake news." So he has incentive to lie just so he'll be criticized for it. He might as well lie about things he has no reason to lie about, because every lie invites a fact check, and every fact check can be denounced as an attack by media evildoers. It's a wonder he doesn't lie about everything -- his name, the day of the week -- just so he can run up his untruth score in the Post and elsewhere. It's all upside for him when he lies, so of course he's doing it more.
Crossposted at No More Mr. Nice Blog