But you already knew that. John Nichols argues that this is why Arlen matters:

No matter who Obama picks, the chances that his nominee will be confirmed with relative ease have risen significantly in recent days. Pennsylvania Senator Arlen Specter's switch from the Republican caucus to the Democratic caucus moves a key member of the Judiciary Committee into the majority-party camp. If and when Minnesota Democratic Farmer Labor Party candidate Al Franken is finally seated, Democrats will have the 60 votes they need to advance a nomination without having to contend with a Republican filibuster.

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