"I have decided to run for re-election in 2010 in the Democratic primary," said Specter in a statement. "I am ready, willing and anxious to take on all comers and have my candidacy for re-election determined in a general election."
"Since my election in 1980, as part of the Reagan Big Tent, the Republican Party has moved far to the right. Last year, more than 200,000 Republicans in Pennsylvania changed their registration to become Democrats. I now find my political philosophy more in line with Democrats than Republicans."
The move will give Democrats a filibuster-proof 60 vote majority in the Senate, presuming Minnesota's Al Franken is eventually seated. However, in his statement Specter said his opposition to the Employee Free Choice Act -- widely seen as a defense against a Republican primary challenge -- will not change.
Polls had shown that, despite his shift on EFCA, Specter was on his way to losing his seat if he stayed in the GOP. A Rasmussen survey from last Friday had former U.S. Rep. Pat Toomey beating the Senator by 21 points in the primary. More HERE