Joe Sestak Catches Arlen Specter

Given the new political ad that Joe Sestak has released, this new polling information really isn't all that shocking:
Rep. Joe Sestak (D-Pa.) waited for months to hit Sen. Arlen Specter (D-Pa.) for his Republican past on television. And now that he’s finally played the GOP card, airing a spot tying the party-switching senator to former President Bush and Sarah Palin, his message seems to be getting traction.

The daily Muhlenberg College tracking poll of the Pennsylvania Senate race showed Sestak tied with Specter at 43 percent Friday after trailing the senator by nine points just four days ago. Eleven percent of Pennsylvania Democrats say they’re undecided.
So, this now begs a new question: if Sestak beats Specter in the Democratic primary election on May 18th -- what happens in November? The conventional wisdom used to be that Arlen Specter would win the primary and then go on to victory by a slim margin over Pat Toomey.

It looks as though nothing about this election is conventional anymore...