It’s been a tough week for Arlen Specter.  He’s dropped out of the lead in his Democratic primary, falling behind Joe Sestak in exactly the way he feared he would against Pat Toomey in the Republican primary — by losing the base.  In fact, Specter had a difficult time remembering exactly which base he was addressing last night:

The first time Sen. Arlen Specter (D-Pa.) slipped up here Tuesday night at the Allegheny County Democratic Committee’s Jefferson-Jackson Dinner, most in the audience pretended not to notice.

But at the end of his remarks when Specter again thanked the “the Allegheny County Republicans” for their endorsement, many couldn’t help but laugh nervously and shoot did-he-really-just-say-that looks at each other.

We have to give the man a bit of a break here.  He’s switched sides so often that even Specter can’t recall which team’s jersey he wears.  Specter tried getting more firm with his allegiance by praising Barack Obama in a campaign video, but unfortunately, too many people noticed that it was almost a word-for-word rehash of his 2004 ad with George Bush.

That didn’t impress anyone — let alone Obama, who suddenly wants to put some distance between himself and Specter, according to the New York Times:

And while the White House has backed Mr. Specter in the primary, making good on a pledge made when he switched parties just over a year ago, Mr. Obama seems unlikely to make a campaign visit for Mr. Specter before the primary, Democrats said. They said the White House is not eager to be embarrassed by having the president make a last-minute visit on behalf of a candidate who goes on to lose, as happened in the Massachusetts Senate and New Jersey governor’s races.

Maybe Obama learned from Massachusetts, although still too late in this race.  Obama campaigned earlier for Specter, and his loss in the primary would be yet another indication of how low Obama’s stock has fallen.  This time, though, instead of an indication of unpopularity among the general electorate, this would be a failure with Democrats.  That would be even more damaging than the loss of the seat in Massachusetts to a Republican after a presidential intervention on behalf of the Democrat.

One has to wonder whether Specter can run as an independent if he loses the Democratic primary next week.  It certainly couldn’t hurt his political career — because it’s otherwise coming to an end in six days.