Trump is the Republican Party, there is no distinction.
The vast, vast majority of conservatives love him and will vote for him literally no matter what he says or does.
Owning the libs is enough for them, they don't care how bad their material conditions are as long as they get that. Never Trumpers are so few in number that they might as well not exist.
Meanwhile Biden, offering literally no hope or anything worth a shit to people, will convince very few that didn't vote for Hillary 4 years ago to do so for him this time around. Not enough to win at least.
It's like Chapo said: The choices are screaming defiantly into the void as you die and hurting the people you don't like along the way, or dying quietly reminiscing about "the good ol' days".
If those are the 2 choices, the former is gonna be way more attractive to people.
Democrats win the Presidency when they inspire voter turnout. Sure, there are plenty of people for whom "we need to get Cheeto Drumpf OUT" is enough of a reason to vote for Biden, but I feel like the "I'm not Trump" message won't inspire enough turnout.
Democrats win the presidency on sheer numbers. There's just more Democrats than Republicans, and more independents who skew Democrat.