Republicans believe revenge is a dish best served hot, on Arlen Specter's face. The 2010 election will be here in no time, so no wasting time reminding people Specter was George W. Bush's big crush.

The National Republican Senatorial Committee launched a robo-call campaign directed at 100,000 Democratic voters. The call includes a quote from the former president talking about how much he loves Specter, the senator who yesterday switched to the Democratic Party from the Republican side.

Then it reminds them he's against card-check union votes, a huge priority for organized labor right now. Have fun campaigning for this guy, Mr. President!

Specter is now already playing serious defense, having been framed as both a turncoat opportunist and now as a Bush patsy. He should have come out of the gate yesterday blasting, tying himself to some key issue instead of just blathering about how he couldn't get elected without switching parties. But he's a sitting senator so he's probably still unbeatable.

(Update: We originally referenced the 2009 primary, but Specter's senate seat is up in 2010.)