GOP's Mike Castle of Delaware, nine-term congressman, puts Republicans in strong position to pick up a Senate seat in 2010, whether or not Beau Biden (D) enters the race.
Six other Republican senators have announced they’ll retire. The exits are a sign the GOP sees itself in 'back seat' for years, say analysts.
To overcome scary electoral math, the GOP must recast its principles.
Tuesday's switch by the independent-minded Pennsylvanian also helps Democrats to solidify power in the Senate.
The business community says the bill, which makes it easier for workers to unionize, would be a job killer.