For the past couple weeks, events have drawn our attention to Rep. Joe Sestak (D-PA), who's serving his second term in Pennsylvania's seventh congressional district. Specifically, he's been taking the lead in support of Defense Secretary Robert Gates' budget proposal, which I discussed with him at length earlier this week.

Neither he nor his staff are shy about the fact that he's trying to position himself out in front of this issue, and it's a big one--sure to result in a bruising political fight in the weeks ahead. In a way, he's the natural surrogate for it--a former Navy rear admiral, who's been arguing for similar reforms, both within and outside of the military for years.

But there's also the question of Pennsylvania politics. As my colleague Eric Kleefeld reported yesterday, former congressman and conservative's conservative Pat Toomey has announced that he'll be challenging Sen. Arlen Specter (R-PA) in the 2010 primary. Specter is very popular in Pennsylvania, but not particularly popular among its conservative residents. If he wins that primary challenge, he'll be a formidable challenger for any Pennsylvania Democrat. But if Toomey wins, it's a whole new ball game.

And that's where Sestak (may) come in.

He told Roll Call back in December that he wasn't interested in running for Senate. But, obviously, a lot's changed since then--including the size of his campaign war chest. He's raised more than a half million dollars this year alone, and sits on over $3 million worth of loot. And, as of now, he'd only have to defeat one Pennsylvania Democrat--businessman Joseph Torsella--in the primary.

I put the question to his staff this morning and...well, all I can report is that his communications director didn't immediately stand by his statement from December. More to come hopefully, and in the mean time, keep your eye on the Sestak bubble.