That's why I said "remote" possibility. He strikes me as a fairly ordinary dude with a bit of asperger's who over the course of his entire adult life got his ego inflated by sycophants on a daily basis. As a result he seems to think he's some kind of leadership genius, whereas in reality he's essentially in the same position as Kim Jong Un, except he's much smarter. I don't know if he realizes this and just plays along, or doesn't even see it, but that facade will fall over immediately after he enters any kind of adversarial environment, which is something you kinda have to do if you want to run for president.
I'm definitely not a member of the ultra liberal crowd in terms of my politics, I'm friends with many who are. The remote possibility that he'd be president is more of a nightmare for them than a wet dream.
Let me put it in more obvious terms: if he were to run against Trump in 2020, who would you vote for? What's a "possibility" is largely determined by circumstances.