Sestak pulls the negative trigger

You could see this one coming from a mile away; the only question among political chin-scratchers is whether there's enough time left in the Democratic Senate primary campaign for it to do its damage. (Possibly; it's a good ad.)

Rep. Joe Sestak started airing an ad, at least in the Philadelphia broadcast market, that attacks Sen. Arlen Specter's Republican past and hangs Bush, Santorum and Palin around his neck. This after nearly three weeks of running two ads: a :60 bio spot featuring his Navy career and cancer-stricken daughter and a :30 spot complaining that Specter was smearing his military service.

The new attack piece begins with an unflattering close-up of Specter as he says, "My change in party will enable me to be re-elected." Then there's timeless footage from Specter's 2004 GOP primary, when Specter faced a brutal challenge from then-Rep. Pat Toomey, a conservative who will be waiting for him in the fall if he survives the primary in his new party. George W. Bush calls him a "firm ally" and someone he can count on "when it's important." Then Specter does the classic arms raised pose with the president and former Sen. Rick Santorum, who was helping the moderate senator with the GOP base. Later, he's shown next to Palin.

The tagline: "Arlen Specter switched parties to save one job...his...not yours."

Pa2010's Dan Hirschhorn saw it on CBS 3. Your correspondent saw it on NBC 10 in Philadelphia. Probably be everywhere soon.