I've got no problem with them declining to support the boy president, but I think their reasons are bad. I don't think the guy's done anything to warrant respect, and he's damn sure not one to show respect for those he doesn't approve of. The idea that you have to respect the office has always been a little lame to me, and now that the office is actively blasting all dissenters, regardless of their rationale, even more-so. Rather than saying he's illegitimate because of Russia, one of them should just say "he's an imbecilic man-child and I'll be taking in a movie tomorrow."
For the record, I had no problem when Grabby was refusing to say he'd concede the election if he thought it was shady. Something the people blasting the democrats here seem to have forgotten.
Lastly, while I've got no problem with it on a philosophical level, the stupidity of the democratic party is pretty astonishing. They're buying right into the game that cost them the election in the first place and doubling down.