the democrats are not credible opponents of fascism

And yet there is no other alternative that actually exists, so we're stuck with them, credible or not! The only -- only! -- way forward that has even a slim chance of success is to try to get better people to win Democratic primaries, not to suicidally punish them in the general election. At that point, they're the least-bad option no matter how feckless they are!

That's reality in accordance with the cold hard math of game theory, and nobody gives a fuck if you like it.