Flipping Senators

If the new Senate splits 50-50 or 51-49 Democratic, we would find ourselves in a situation where one Senator switching parties would alter the balance of power. This could be a good time to take a look at this and see who might be up for grabs.
Usually, a politician changing parties is limited to a few specific cases. Either 1) he feels out of step with his old party or 2) his old party is out of step with his state or 3) his re-election chances would be better if he switched – sort of a tactical/craven version of #2.
Add in the reluctance of a recently elected Senator to switch because he a) ran with party endorsement and b) took lots of party money and would be trusted by nobody if he then switched, and we can narrow down the potential jumpers.
On the Democratic side of the aisle, the Nelsons just got re-elected, the two Arkansas Senators seem unlikely to split up, and Salazar is a recent enough electee to not have a good reason. I guess Robert Byrd could switch, but he would probably die if he tried to cross the aisle. Lieberman is just sleazy enough to do it, but he’s running with the express promise to caucus with the Democrats and that could open a really nasty can of worms if he tried to move over. That leaves Mary Landrieu as the lone possibility. I actually thought she was a good possibility for this back in 2004, when it looked like running for re-election in LA as a Democrat could be a dicey proposition. She is quite conservative on a number of issues and would easily fit over there as a moderate Republican. The Landrieu family goes way back in LA party politics and her father, Moon, was Mayor of New Orleans and her brother, Mitch, is Lt. Governor of LA. Still, they might have understood her problem and not disowned her, that is, until Katrina hit. The concept of her joining up with the Bushies at this point is laughable, so there goes the GOP’s last chance as I see it.
On the GOP side, they have very few moderates left. Snowe just got re-elected and Spector owes his re-election in 2004 to the party and Bush in particular, so they’re out. That leaves us with Susan Collins. Collins won easily in 2002, with 58% of the vote and considering Snowe is having no trouble in Maine this year, one could assume she would have little reason to move. The difference between Collins and Snowe is that the religious right sees Snowe as invulnerable. They already have Collins on their RINO hit list for 2008 and are openly lusting for her defeat. She could be in for an expensive primary battle, followed by a serious general election. On the other hand, if she follows the Jeffords route and becomes an Independent and caucuses with the Dems, she gets to run without a primary fight and, following the Sanders precedent in VT, the Dems won’t bother running anyone against her. This is the easiest re-election possible vs. two tough battles – it seems an obvious choice in the strategic sense. She could then form the core of the Whiny Independent Caucus with Joe Lieberman and things would work out fine. Do I think she’ll do this? Not really, but it’s something to root for if things end up 50-50.