That boulder Joe Sestak is pushing up a hill just got a lot bigger.

And the hill is now a lot steeper.

That’s because, despite more than 2 feet of snow, the state Democratic Committee met Saturday in Lancaster. It did not go well for the upstart congressman from Delaware County. They gave their blessing to Sestak’s foe, Sen. Arlen Specter.

Sestak gave up the 7th District seat he wrestled away from 20-year incumbent Curt Weldon and the GOP, only to give it up after less than two terms to seek the Democratic nomination for U.S. Senate.

An equally imposing force of politics stands in Sestak’s way this time around as well.

Specter switched parties and was welcomed with open arms by everyone from President Barack Obama, Vice President Joe Biden and Gov. Ed Rendell.

But someone forgot to invite Sestak to the party.

Irked at what he believes was a heavy-handed effort to clear the path the Democratic nomination for Specter, Sestak got into the race. And he’s not getting out, despite lagging in the polls.

Even the state Democratic chair indicated publicly Sestak was hurting the party with his run, and everyone would be better off if he got out of the race and ran for re-election to the U.S. House. Well, maybe everyone but Bryan Lentz, who himself is giving up his Pa. House seat to seek Sestak’s spot in Congress.

But the calls have fallen on deaf ears.

On Saturday Sestak took another body blow, when the state committee voted overwhelmingly to endorse Specter.

Sestak, the former admiral, is not yet ready to abandon ship. He said he fully expected the move and branded it merely another example of the kind of insider politics that he is fighting.

He said he was “a little too independent” for the committee members, and vowed “this is going to be a great fight.”

In other words, the admiral is sticking to his guns. Even if all the experts tell him he’s about to go down with the ship.