Arlen Specter jumped parties in order to avoid a tough Republican primary fight against Pat Toomey this year, even though the national party had sent every signal that they would back Specter in the rematch of the 2004 primary Specter narrowly won.  Instead, he leaped from the frying pan into the fire of a Democratic Party primary against Rep. Joe Sestak.  And even though Specter has the support of the White House and the national Democratic organizations, Rasmussen shows that Sestak has overtaken Specter with just a week to go:

Congressman Joe Sestak has moved ahead of incumbent Arlen Specter in their Senate primary match-up with just over a week left before Pennsylvania Democrats go to the polls to pick their nominee.

The latest Rasmussen Reports telephone survey of likely Democratic Primary voters in the state shows Sestak earning 47% of the vote while Specter picks up 42%. This marks the first time Sestak has held the advantage in the race.

Specter’s support has slipped from 48% in March to 44% a month ago to 42% today.

The numbers for Sestak have been going in the opposite direction from 37% in March to 42% a month ago to 47% today.

Pennsylvania has closed primaries, one of the reasons that Specter defected last year.  With his support as a Republican coming in large part from independents, he knew he would get clobbered by Toomey this time around among an all-Republican electorate.  It’s not getting any better for Specter on the other side of the aisle.  Democrats prefer Sestak, who didn’t just show up as a Democrat, and certainly not just to save his own political skin.

Interestingly, Democrats still give Specter high marks — in fact, higher than Sestak.  Specter has an approval rating of 67% to Sestak’s 63%.  (Obama’s is 80% among likely Democratic primary voters.)  But voters perceive Snarlin’ Arlen as much more negative than positive on the campaign trail, 35%/22%, while Sestak is seen as more positive, 11%/39%.  Specter has a narrow edge among women, 47/40, but Sestak has a 24-point lead among men, 58/34.  Sestak also has overwhelming advantages among young voters, carrying the 18-29 demo 87/13, and in the 40/49 demo 54/24.  Specter only has a majority among thirtysomethings, 52/40, with the two splitting the other age demos.

Two other fascinating data points.  Among Democrats who favor repeal of ObamaCare, Sestak wins 59% of those who strongly favor repeal and 62% who somewhat favor repeal — as well as a 49% plurality of those who somewhat oppose repeal (Specter gets 38% of that demographic).  Specter gets 66% of the “not sure” votes, which just about sums up Specter’s career over the last thirteen months.

Lastly, this poll of likely Democratic voters show that they narrowly approve of an Arizona-like immigration enforcement law, 46/45.  That law looks more and more popular as it becomes more well known.

Update (AP): More bad news for the RINO turned DINO: A new poll from Muhlenberg of likely voters is right in line with Rasmussen. Sestak 46, Specter 42.