One of the older clichés in politics is that of "projection." But on occasion, the cliché is transcended by screaming obviousness.
Welcome to the race Sleepy Joe. I only hope you have the intelligence, long in doubt, to wage a successful primary campaign. It will be nasty - you will be dealing with people who truly have some very sick & demented ideas. But if you make it, I will see you at the Starting Gate!
— Donald J. Trump (@realDonaldTrump) April 25, 2019
The one potential candidate the White House has feared most since 2017 is Joe Biden, chiefly because his reputation of decency so conflicts with — and highlights — Trump's utter depravity. But Biden is no longer a Trumpian fear. He's a reality that Trump can battle only with adolescent charges of Biden's low intelligence, surrounded by a Democratic field of "sick and demented ideas." And that's a twofold whammy of Trump's psychological projection — absolute r=terror on his part.
Such puerility worked in 2016, as a political novelty. I doubt it fly in 2020.