Snarlin’ Arlen is turning on the charm.

And Joe Sestak is no doubt about to turn on the heat.

Sestak made his first appearance in front of state Democrats over the weekend at a party gathering in Pittsburgh.

You’d be hard-pressed to know the guy was ever a Republican, if not for his own admission that he fled the GOP and is now “pleased and proud” to be a card-carrying member of the Democratic Party.

Specter joked that he had often been mocked in some GOP circles as a RINO – Republican In Name Only. Now he’s not ever that.

Also on hand was Sestak, the two-term Delco congressman who has Specter squarely in his crosshairs.

Sestak continues to question just how much of a Democrat Specter will be, noting he has yet to fully endorse the agenda of President Obama.

Sestak says that while the party leaders are solidly in the Specter camp, he heard from many on the floor that they would like another choice.

Stay tuned. This one is going to get interesting.