Wow a lot of vitriol for Bobby Scott. Don't know why, he's never done anything embarrassing, has a solid voting record, and while he hasn't shown himself to be a strong fundraiser, he doesn't really need to in a district as D leaning as his. I'd certainly rather have him than either Beyer or Connolly.
I have nothing against Bobby Scott per say (if electability weren't an issue, he'd be among my top choices to fill the vacancy tbh) and wouldn't mind so much if there were more of a cushion in the Senate (ex: if we had a 52-48 or 53-47 majority which, while possible, is still pretty unlikely), I just really don't think an African-American liberal from Newport News with weak fundraising, no experience running in a non-safe Democratic district, much less in a truly competitive race is going to hold a Virginia Senate seat against even a generic Republican in an off-off year election with a Democratic President who will probably be pretty unpopular. Given those circumstances, Beyer and Connolly would both be much stronger candidates to keep the seat in Democratic hands. Plus, Scott will be 71 by the time the special election rolls around.
That all being said, if you want to go with a solid liberal who has proven that he can run far ahead of his party and hold his own in a tough environment and/or don't want to pick someone from NOVA for whatever reason, why not appoint Tom Perriello?
