I think he'll win because the left is very fundamentalist these days, and the dem candidate can be forced to carry very unpopular positions held by parts of the left because it's all shoved under the greater SJW umbrella. By the time the election comes, Trump will have forced the dem candidate to support pedophilia, fat acceptance, taxpayer funding of troon surgery, etc. Things even normies who lean left see as a step too far, but the candidate has to defend them because that's what the left is, a monolithic cult in which no dissent is tolerated. If the candidate ever dares say "I'm not so sure we should be pumping children with puberty blockers just in case" (s)he'll be cannibalized by the party, they'll switch to someone else a week before the election if necessary.
But, who knows. There's hard evidence of widespread vote tampering in at least five states in 2016, plus last year all the court challenges that got vote results flipped to democrats for congress, so they might be able to scam out a victory.