"I found myself increasingly at odds with the Republican philosophy and more aligned with the philosophy of the Democratic Party." - Senator Arlen Specter

It seems that feeling is fairly widespread these days among moderate (now ex-)Republicans, especially in the great state of Pennsylvania.

The senior United States Senator from the state of Pennsylvania, Arlen Specter, has decided to become a Democrat.  This is a game changer.  Not only does this mean Democrats are all but certain to gain 60 seats once Al Franken is rightfully seated, it could provide cover for more party switches, with rumors flying that Maine Republican Olympia Snowe may be next.

Now, what this means for real legislation has yet to be seen.  While Arlen has said he doesn't plan to change his positions on important issues, it seems all but inevitable that he'll need to get in line with Democratic priorities if he intends to survive a Democratic primary and stay in the good graces of Democratic leadership.

This leaves open the question of what's going to happen with the Employee Free Choice Act.  Arlen said he's not going to invoke cloture and thinks it's a bad idea, but he's sponsored this bill in the past as a Republican.  You can be sure that labor unions will push him hard on this issue, and mount a spirited primary challenge if he plays a part in blocking the passage of EFCA.

Watch him explain his reasons for leaving in this youtube video: