Yesterday, Senator Rick Santorum (R-PA) had this to say about his Democratic colleagues:

"The audacity of some members to stand up and say 'How dare you break this rule' -- it's the equivalent of Adolf Hitler in 1942 saying 'I'm in Paris, how dare you invade me. How dare you bomb my city. It's mine.' This is no more the rule of the Senate than it was the rule of the Senate before not to filibuster. It was an understanding and agreement, and it has been abused."

Apparently, Santorum now understands that calling your opponents Nazis is beyond the pale of reasonable discourse. The Pittsburgh Post-Gazette's Maeve Reston has the story:

Santorum issued his own clarification yesterday evening, stating that the reference to Hitler was "meant to dramatize the principle of an argument, not to characterize my Democratic colleagues."

"My point was that it is preposterous for someone to trample a well-established principle, and then accuse his opponents of acting unlawfully when they try to reestablish that principle," Santorum said. "Nevertheless, it was a mistake and I meant no offense."

Santorum has a history of making bold comments (he likened gay marriage to men having relations with canines), yet never seems to learn that there he -- as a Senator -- is expected not to embarrass his state on a regular basis. Santorum might learn his lesson soon, however, as he trails Democratic challenger Bob Casey by 14 points in recent polling.