That Took A Little Longer...

... then I thought, but I was right even if out by a year or so. Arlen Specter to switch parties.

http://voices.washingtonpost.com/thefix/senate/specter-to-switch-parties.html

Specter has a strongly supported nomination challange by Toomey to deal with, a state strongly trending blue, and open hostility with members of his own party over his largely moderate (dubbed RINO) political views. Switching parties gives him a chance to win another term in the Senate, something that would have been impossible even if he did survive the GOP nomination.