At The Washington Post, Chris Cillizza and Aaron Blake note that the battle for control of the Senate is basically a toss-up:
Assuming King wins and picks the Democrats, Republicans would need four seats to take over the majority if former Massachusetts governor Mitt Romney wins and five seats if President Obama is re-elected. (The vice president serves as President of the Senate and casts tie-breaking votes when necessary.)
So, how do Republicans get to four (or five)? Nebraska is an almost certain pickup, with polls showing state Sen. Deb Fischer (R) with a comfortable lead. North Dakota's open seat is far more competitive than most people expected (including us) but it's still a state that should go solidly for Romney in November, which will help Rep. Rick Berg (R). The Republican field in Missouri is mediocre, but Sen. Claire McCaskill (D) isn't likely to be able to get enough distance from Obama to save herself.
The easy way to put this is that the Republican Senate majority depends entirely on Mitt Romney's performance in November. If Romney wins with even a slight majority, then-given the decline of split-ticket voting-odds are good that Republicans have picked up a seat (or two) in either Montana, Wisconsin, or Virginia. By contrast, an Obama win-which would imply high minority turnout-would likely result in a narrow Senate majority for Democrats, and a smaller House majority for Republicans. In other words, we would have a variation on the status quo.
It should be said that this puts lie to Obama's promise to "break the stalemate" if he wins re-election. Republicans have no incentive to be The moderate; as time goes on, it becomes much more difficult for the incumbent party to maintain its hold on power. If Republicans hold on to their right-wing intransigence, they'll eventually be rewarded; Democrats will lose their grip on the White House and their majorities in Congress, and the GOP will have the space it needs to pursue its agenda.
