I've gotten a couple of e-mails asking for comment on next week's Pennsylvania Senate primary, in which Joe Sestak appears to be surging against Arlen Specter and has overtaken him in new Rasmussen and Muhlenberg polling.
This is one of those times where the obvious answer seems to be the right one: the surge is probably real, and Arlen Specter may be in a great deal of trouble.
Yes, Muhlenberg's sample sizes are a bit small, and Rasmussen's polling has been a little weird this year. But there are no polls -- yet -- that contradict them (there are plenty of other polls, but they're out of date). In primary elections, late movement is often the rule rather than the exception, and that may be especially so in a race where one of the candidates (Sestak) started out with a substantial name recognition deficit, where a lot of voters had waited to make up their minds, and where one of the candidates (Sestak, again) had a spending strategy predicated on peaking at the right time.
Plus, it's not as though the minds of Pennsylvania Democrats are hard to read. Specter, although he's compiled a reliably liberal voting record since Sestak's challenge began, seems to be motivated primarily by political expediency. Sestak, for that matter, has been a bit opportunistic himself -- posing as a hardened progressive when his voting record is significantly more moderate -- but he's basically a Generic Democrat running somewhat to his left in the primary, as Generic Democrats usually do. His chances of winning the general election appear to be about even with Specter's from a statistical perspective, and are perhaps better going-forward as he has considerably less baggage. He ought to be a fairly comfortable choice for primary voters.
Bear in mind that primary polling in general is pretty bad, and that when it misses, it often misses in the same direction. So even if all the polls show Sestak with a 5-point lead in advance of Tuesday's voting, there'll still be a decent shot that he could lose. But the election now appears to favor him.