I can't see how the Democrats don't suffer somewhat from the follies affecting Messrs Northam, Fairfax, and Herring. How badly that will hurt remains to be seen.
Basically none, considering all three will be a non-factor by the 2021 race (neither Fairfax nor Herring are winning the primary). Especially considering the fact that the most damaging potential folly either party could make would be the Republican primary electorate picking Amanda Chase as its standard bear for the gubernatorial, which seems like a real possibility. She makes Corey Stewart look sane.