If this is how he felt the last year, he's just as culpable as all of the other fucks who stayed home and didn't vote. Fuck him and his Monday morning quarterbacking.
The republican party and adjacent is mostly white nationalists, what would make you think that they would switch to voting for a Jewish person? He would have unfortunately lost.
No point in arguing with the Bernie Bros. It's analogous to the MAGA cult at this point, the blind devotion. The only difference was Trump was able to win his primaries.