The sudden retirement of long-time Maine Senator Olympia Snowe may spell the end of Republican hopes to take back the Senate this November. Although both of Maine's senators are Republican, the state generally leans blue, and Nate Silver argues that the Democrats are better positioned to take over Snowe's spot. The two most likely candiates right now are Maine's two Congressional Representatives who both won their last election comfortably and are well-known and well-liked at the state level. A tight filing deadline makes it tough for anyone else to pull together a suitable alternative, but no matter which one survives a primary, the two Dems are likely to beat any "generic" Republican.
As if the loss of Snowe wasn't bad enough, Republicans have not gotten much traction in other races, either. With more than 20 Democrats up for re-election, the GOP was looking to unseat a few vulnerable Democrats in 2012 and overcome their four seat minority. But suddenly the party finds that some of their own incumbents are the ones in danger of losing out. Scott Brown is in a tough fight with Elizabeth Warren in Massachusetts. Others, like Richard Lugar of Indiana, are facing big Tea Party primary challenges, and Republicans have struggled to find quality candidates in other areas. The return of Bob Kerrey makes a GOP win in Nebraska — which seemed like a lock after the retirement of Democrat Ben Nelson — less certain as well. If the economic situation continues to trend in President Obama's favor, the angry "throw the bums" out rationale loses a lot of its steam, and a presidential re-election would sweep more than few party members along with him.
It also didn't help that Snowe stepped down while firing shots at her colleagues back in Washington. While both sides are to blame for what she calls "‘my way or the highway’ ideologies", the fact that she didn't stand up for her own party members could feed the sense among voters that a reasonable moderate was pushed out by her more hardline co-workers. (She was "one of the good ones," you know?)
In the end, all Congresspeople are so disliked that both Democrats and Republicans will have a hard enough time holding on to their current seats without having the luxury of taking some away from the other guys. That leaves us right back where we started. Gridlocked.