We at the Daily Horse Race are stunned to hear this news. While we will have a more analytical update on this later, we must report that Arlen Specter is to announce later in the day that he will be switching political parties. Arlen Specter is expected to become a Democrat.

This is HUGE news. If Al Franken is seated, the Democrats will have the fillibuster proof majority.

Source: http://edition.cnn.com/2009/POLITICS/04/28/specter.party.switch/