If Romney wins but Ds maintain a 51-49 majority (best case D Senate scenario in the event of a Romney victory, pretty much), Joe Manchin basically turns into the Senate's single most powerful member. That could be fun. Doesn't he support healthcare repeal, or am I kidding myself?
If he does vote with the Republicans for successful Obamacare repeal, then he should be expelled from the Democratic caucus. \_/ as to whether that would hurt our majority or whatever.
Also, what would make you say a 51-49 majority a best case D Senate scenario? I'd say it'd be like 53-47.