Tuesday is not turning out any better for Arlen Specter. Not surprisingly, Rep. Joe Sestak isn’t much impressed by the Specter Democratic roll-out and seems poised to jump into the race. This report of his appearance on a local radio show suggests we have a Democratic primary brewing:

Rather than step aside for the party-jumping Specter in next year’s Democratic primary, Sestak sounded ready to battle the 79-year-old senator, who has the backing of President Obama and Gov. Ed Rendell in a deal worked out in advance of the shocking announcement that he was leaving the Republican Party.

“The reason I got into politics was not to have the establishment re-establish the establishment — whether it’s my party or any party,” Sestak, a two-term congressman from the Philadelphia suburbs, said on the air. “This is about what are you doing for the people of Pennsylvania. It isn’t about Arlen. It isn’t about me. It isn’t about whether he is going to lose his job or not. Too many Pennsylvanians have lost their jobs.”

So what does the White House do now? The liberal base is disgusted, Big Labor is annoyed, and Specter’s polling numbers are unimpressive. But Obama pledges to campaign and raise money for Specter. Well, he didn’t say how much.

This is one of the rare cases in which the White House got the politics wrong. Now the trick will be to avoid spending too much of the president’s political capital on a poor investment.