We’re in a timeline now in which truth is entirely irrelevant.
Trump supporters are necessarily one of two things - deluded or dishonest. Either they’ve been manipulated into not seeing the plain fact that he’s a corrupt and self-serving autocrat and an existential threat to the US, or they know exactly what he is and just don’t admit it publicly.
In either case, truth and reality count for nothing.
I sincerely have no idea.
The narrative that a leftist couldn’t win is repeated so predictably and so often and by so many people that the whole idea has become sort of detached from reality, and there’s no telling what would happen if it was actually a possibility.
And particularly since the one thing I’d pretty much guarantee is that the concerted efforts on the part of the ruling class to prevent a leftist from running would be as nothing compared to what they’d do and say in order to prevent one from winning.