Nate Silver crunches the numbers. It looks like Joe Sestak's primary challenge has made Specter a pretty loyal Democrat (which is what TNR was hoping for when we wrote this editorial). Of course, the problem for Democrats, as Silver notes, is what happens if/when Specter beats Sestak in the primary--especially since Pat Toomeny, his likely Republican challenger, might actually pose a significant challenge. Does Specter begin to shift back to the right?

All of this is enough to raise the question--perhaps a bit prematurely, but still--of whether the Democrats were right to welcome Specter into their party. As the recent Q-Poll that found Specter neck and neck with Toomey showed, he's got some serious problems--the most significant one being that 49 percent of Pennsylvania voters feel he doesn't deserve reelection (40 percent think he does deserve to go back to Washington). Would Democrats have been better off telling Specter he wasn't welcome in their party, and then running Sestak against Toomey (who presumably would have beaten Specter in a GOP primary) in the general election?

--Jason Zengerle