A new Daily Kos/Research 2000 poll finds Sen. Arlen Specter (D-PA) in good overall shape to win re-election in 2010 -- though there just might be an opening for a Democratic primary challenger.

In a Democratic primary against the lesser-known Rep. Joe Sestak, Specter has 56% to Sestak's 11%, and Specter also leads current challenger Joe Torsella by 60%-5%. However, a separate question shows that only 37% of Dem primary voters say they would definitely vote for Specter, while 23% would consider someone else, 16% are definitely for someone else, and 24% are undecideds. This would indicate that some of Specter's support is soft, and a challenger could have a plausible (though definitely uphill) chance.

Dem primary respondents were asked whether they would be more or less likely to vote for Specter if they knew he'd voted against President Obama's budget, or the Employee Free Choice Act, or health care. In all cases nearly half of respondents said it would have no effect, and about one-quarter said it would make them less likely to support him. It could be that if Specter were to vote too much against the Obama agenda, a challenger could potentially hammer those issues and shift some of these numbers around.

The bottom line, however, is that Specter is the heavy favorite, and would have to continue to make a lot of mistakes in order to blow it.

The poll also corroborates the general consensus that former Rep. Pat Toomey, whose conservative primary challenge scared Specter into switching parties, is unelectable against Specter -- and even against Democrats people haven't heard of. Specter has a healthy lead of 55%-31%. With Sestak as the Democrat, it's a 37%-32% Dem lead, and Torsella edges Toomey 35%-33%, with greater undecideds because the Dem candidates are less well known than Specter.

Interestingly enough, this poll has a very different Republican primary result than the Public Opinion Strategies (R) survey from two days ago, which had Tom Ridge beating Toomey in a landslide. Instead, this poll gives Toomey a 41%-33% lead. In a general election, this poll also has Specter in a dead heat with Ridge, with 45% for Specter to 44% for Ridge. Of course, this point appears to be moot now that Ridge isn't running.