I think these are particularly strange results, no?

According to Rasmussen, "Among voters who favor the congressional health care plan, Specter leads 55% to 26%. However, among those who oppose the plan, Sestak leads 61% to 25%." It's unclear how this divide emerged, but since support for reform among Democrats in the state is around 70 percent, don't be surprised if you see both candidates try to stake out the reformer position on health care.

Strange because Sestak and Specter both support a public option (although I'm skeptical of whether Specter really supports it but for the moment lets take things at face value). My best guess is that these days Specter is perceived as a Washington-insider since he has the support of the White House and Sestak's rebellious campaign implies to some that he's radical in his policies and doesn't fall lock step with the regular White House Democratic circle. Or maybe it's just a bad poll.
Of course, the truth makes this all rather ironic since Specter is the real radical and Sestak is more the Obama Administration darling but I suppose it's ironic too that in this situation the White House is supporting Specter.