Big news out of PA politics today, as Senator Arlen Specter announced he is switching parties, to become a Democrat. He will run as a Democrat for the 2010 election.

Sen. Arlen Specter

Specter was facing a brutal primary fight against Pa. politician Pat Toomey.

According to news reports, President Obama called Specter to welcome him to the party. The Democrats have good reason to celebrate: with Al Franken likely to be able to finally take office, and Specter’s switch, they now have a filibuster-proof majority.