The Democrats face two potential dilemmas in the Senate. The first one is easy: If they win the Senate seats still up for grabs, then they have to make nice with Senator Joseph Lieberman in order to secure a filibuster-proof majority.
The second one is a a lot trickier: does it really make political sense to expel convicted felon Senator Ted Stevens if he scrapes by in the Alaska election? For one thing, Stevens is a Republican problem, not a Democratic one. If he refuses to resign, then voters apart from the apparently more forgiving Alaskans will be constantly reminded of his corrupt ways.
What's more, evicting Stevens could simply open the door for a Senator Sarah Palin -- a vital step in her quest to airbrush her image. As Senator, Palin would surely depict herself as a kind of Mrs. Smith goes to Washington, setting the stage, as she clearly hopes, for 2012.
On the other hand, if you figure that more exposure to Palin will further disenchant the electorate with her charms, then a Palin in Washington might not be such a bad thing. But serving in Washington would unquestionably polish up her resume, allowing her to claim both executive and national experience as well as having weathered the presidential campaign trail in 2008. The bottom line is this: John McCain's true legacy isn't losing the presidential election. It's creating Sarah Palin.