Trump isn't like past Republican leaders. He is an insurrectionist for starters. If he gets in, he'll be trying to stay in the rest of his life. Changing the constitution and corrupting elections utterly. Sorry Biden isn't ideal, but he's far better than Trump.
But there are elections where it's less wrong. I'm pretty sure Trump's team will be spreading progressive disillusionment. It will be progressives more likely to disengage, or splinter. Those same progressives can't then complain they got Trump. And maybe they won't get another real vote again to seperate him from power.
Non-voters, and third party voters, will be just as responsible as Trump voters for a Trump victory. That is the realpolitik.