Right now, we're 21-18 in the State Senate. If Republicans win in the vacant VB seat (hardly a sure thing), that would be 21-19. If McClellan wins and vacates her state legislative seat, that would make it 20-19, so still a Dem majority in the State Senate.

Not to mention that McClellan would only be vacating her seat on on like February 22nd, which is only a few days before the State Senate session ends. So there would only be a brief 20-19 period of a few days.