A new Susquehanna poll shows former Gov. and Homeland Security Secretary Tom Ridge (R) beating newly Democratic Sen. Arlen Specter in a general-election matchup, reinforcing Quinnipiac's finding that Ridge would have a better shot at winning the seat for the GOP than would the more conservative Pat Toomey, whose gigantic primary lead over Specter, some say, forced the Senate veteran out of the GOP's ranks.

Quinnipiac found that Specter would beat Ridge 46-43 percent; Susquehanna has Ridge up 39-38 percent. Of course, these numbers could shift significantly between now and 2010.

Perhaps a more relevant question is how Ridge would fare against Toomey in a primary matchup, and no one appears to have measured that. Ridge will have to beat Toomey for us to see a Ridge vs. Specter general election. (Though, presumably, Ridge's advantage in general election viability could help him gain votes in a GOP primary.)

The Ridge vs. Toomey scenario would allow us to learn something about Pennsylvania Republicans. When Arlen Specter decided to become a Democrat, he said the Republican primary electorate in PA had shifted, becoming more conservative. That take seems to be supported by the fact that Specter one day trailed Toomey by a vast margin in support among Pennsylvania Republicans, and the next he led Toomey by a vast margin among all voters in the state: Republicans's strong preference for Toomey's conservatism was proven to be out of line with what Pennsylvania thinks as a whole.

Hearing Specter talk about Pennsylvania GOP primary voters (and reading about how they jeered him for voting "yes" on the stimulus) makes Republicans in the state seem, indeed, far from the center. Their choice between Toomey and Ridge might give us a window into what value they place on general election viability, how they relate to a more moderate Republican, what they think of abortion--Ridge has said he is pro choice--and whether they are, as some would portray them, hard-core ideologues.

Insofar as Specter's switch tells us anything about the national GOP, those questions about Pennsylvania's GOP base are nationally significant as well.

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