In recent weeks, Rep. Joe Sestak (D-PA) has become one of the most visible figures in Pennsylvania politics, and his star is still rising. We noted a couple weeks ago that, in a number of ways, Sestak would be well positioned to run for Senate in 2010, but he's said all along that he's happy serving in the House and has no intention of attempting a switch.

Now, of course, the landscape is completely changed. And whether Sestak throws his hat in, or stays in the House, Pennsylvania Democrats will have to decide whether or not to embrace Democratic Senate candidate Arlen Specter. On that question, Sestak's saying 'not'--at least for now. Watch:

In a sense he's shifting parties because he found it hard to run against someone. So I'm interested to see what he's running for.... I'm going to have to wait because if the alternative is Toomey, that's one issue. In my mind this is an extremely important moment in the sense of accountable leadership. Their decision has been made that it's easier to run somewhere else and so we've got to make a decision: Is that the type of individual we want to take us forward?

I wonder which individual Sestak has in mind....