What happens in a 50-50 Senate?

The fate of the House seems mostly certain this morning, but what of the Senate?  Republicans would need a Herculean effort to win 10 seats and take back the upper chamber; most predictions have them falling somewhat short, with gains between 6-8 seats, which would be very impressive in and of itself.  What happens, though, if the GOP manages to win 9 seats?  According to the current party affiliations in the Senate, that would create a 50-50 tie — and potentially set off a game of musical chairs.

First, the most obvious consequence will be that the upper chamber gets to see a lot more of Joe Biden.  The VP will have to cast deciding votes for 50-50 ties, including organizing the Senate for leadership.  That means he will have to be close at hand for any important and debated bill, because the Senate won’t wait for hours to get Biden’s vote if he’s traveling around the country touting “Recovery Winter” for the Obama administration. Of course, there will be fewer such bills if the GOP can reject cloture on anything unpalatable, which will likely happen often.

Less obviously, the composition and leadership of Senate committees will change.  Traditionally, a split Senate means split representation on the important panels that control the flow of legislation and approve presidential appointments.  Expect the Democrats to follow that precedent only grudgingly, if at all, and that may depend on whether the combative Chuck Schumer or the slightly more accommodating Dick Durbin winds up as Majority Leader.  If they do follow precedent, expect only those bills on which substantial bipartisan agreement exists to make it out of those committees at all, and for the tenor of Barack Obama’s appointments to change out of necessity.  There will be no more Van Joneses or Dawn Johnsens.

But will such a Senate remain evenly split for long?  As the stakes rise, both parties will be looking for potential party-switchers to gain an advantage.  Sean Trende gives the top 5 candidates for a switch at RCP, and you might (or might not) be surprised at who he sees as the most likely candidate:

Olympia Snowe – For all the talk of a switch among Democrats, the most likely switch probably comes from the Republicans.  Snowe had to be watching with horror as Arlen Specter left the party in advance of a surefire primary loss, and then fellow moderates Lisa Murkowski and Mike Castle lost Senate primaries to very conservative candidates.  Her party has nominated a very conservative candidate for governor in two successive elections, as Maine moderate and liberal Republicans have switched their registration to Independent or Democrat.

She’s already cast a vote for a version of the health care bill, which makes her odds of surviving a primary challenge in 2012 fairly slim.  But she also has to fear the “Specter treatment;” if she were going to make this move, it probably would have made more sense to make it in early 2009, giving her four years to build up her Democratic credentials.  Chance of a switch:  15-20 percent.

Most of the speculation will focus on the GOP wooing Democrats, but this is a good reminder that both parties can play the game. It’s important to keep 2012 in mind, though, when far more Democrats than Republicans will have to defend their seats.  Switching to the Democrats now would mean prepositioning one’s self for minority status in two years, all to join a majority that probably won’t get to do anything with their power, thanks to a firm GOP grip on the House.

Trende sees Ben Nelson and Mark Pryor as the best prospects for conversion to the GOP, Nelson because his state is deeply red, Pryor because his colleague Blanche Lincoln is about to suffer a humiliating defeat — and they’re both up for re-election in 2012.  However, both voted for ObamaCare, which won’t exactly endear them to voters anyway, and both would likely face primary challenges in the GOP if they switched.

Given the likely-strong Republican control of the House and a president who may not be inclined or even capable of moving to the center, a 50-50 Senate might produce mainly political machinations.  And, of course, some great YouTube moments from Joe Biden.