Assuming Al Franken is seated in the U.S. Senate, the Democratic Party will now have what it coveted and failed to attain in the 2008 election: a 60-seat supermajority in the upper chamber, and the ability to pass legislation without a single Republican vote, unfettered by filibusters and free to put its consensus directly on President Obama's desk.

Sen. Arlen Specter (D-PA) has given them that opportunity today, switching parties after realizing, as he put it, that his vote in favor of the stimulus package caused a schism that made his differences with the GOP "irreconcilable," as he said in a statement announcing his break.

But it likely won't mean a simple, across-the-board approval of the Democratic wish list. In fact, it may not change much when it comes to some major pieces of legislation.

Specter has always gone his own way, and his statement today highlights that independent streak: "While I have been comfortable being a Republican, my Party has not defined who I am. I have taken each issue one at a time and have exercised independent judgment to do what I thought was best for Pennsylvania and the nation," Specter said.

Indeed, as one of the critical votes on Obama's stimulus, Specter joined forces with fellow moderates Susan Collins (R-ME), Olympia Snowe (R-ME), and Ben Nelson (D-NE) to negotiate a smaller package with more tax cuts, eventually lowering the pricetag to $787 billion from a mark that, at one time, approached $900 billion.

Similarly, as organized labor turned its eyes to Specter as the key vote on the Employee Free Choice Act--its highest-priority bill in decades--Specter offered a floor speech in which he rejected ideological allegiances both to labor and his own party, declaring his intellectual independence and, instead of saying "yes" or "no" to the bill, laid out his own version of labor law reform, essentially mandating his own language as a compromise. Specter opposes the bill as it is written and said in his statement that his stance will not change.

Now that he's a Democrat, things might look much the same. While he has a new party label, he's not that into party labels. And while he'll eat lunch with the Democrats every Tuesday, across the hall from his old party colleagues, he still represents a moderate faction of senators that will form the crux of many legislative negotiations in the upper chamber--signifying a critical vote with enormous power over what language the Senate passes in major policy initiatives.

Simply being around Democrats and their ideas, talking to them instead of Republicans on a daily basis, could influence his thinking. But if we are to take Sen. Specter at his word, he may prove both as troublesome--and, alternately, as friendly--to both parties as he was yesterday.

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