Talking Points Memo reports that Joe Sestak is in fact jumping into the Pennsylvania primary race against Arlen Specter. This comes as no surprise to those following Specter’s bumbling, stumbling defection to the Democratic Party. Sestak, a retired Vice Admiral, will run no doubt as the “real” Democrat and will be happy to pick up all those former GOP ads the Republican Senate Campaign Committee has been using to taunt Specter (George W. Bush loved him!).

The president and Ed Rendell have promised to campaign for Specter but the president is not known to expend his personal political capital on questionable efforts (e.g. the Georgia Senate run-off election). Big Labor is tugging and pulling at Specter but now has a solidly dependable liberal to consider in the race should it choose to throw its weight and finances into the primary.

In the end, the Democratic primary voters will decide Specter’s fate. Has Specter’s craven opportunism finally reached its end? Or will the party regulars welcome Specter, as unreliable and infuriating as he may be, into the fold? It will be one heck of a race. And one other factor: Specter is 79 years-old, hardly out of the age-range of the U.S. Senate but plainly not the future of the party. I would expect that to be an issue.