Sen. Arlen Specter told Senate Majority Leader Harry Reid (D-NV) about his decision to switch parties in person yesterday.
The Hill reports Senate Republican leaders "received no heads up" from Specter about his decision.
Meanwhile, Ben Smith reports Vice President Joe Biden "deeply involved" in the talks with Specter to make the switch.
NBC News says Democrats promised Specter would face no Democratic challenger but that he was promised no committee chairmanship in return for switching parties.