The Role of Race in the PA Primary

David Sirota applies his Race Chasm theory to the Pennsylvania primary in an interesting blog post this morning. The theory is really an observation, but a keen one: Obama tends to win states that have either a) virtually no African-American population, and therefore minimal white-black racial tension; or b) states with an African-American population substantial enough (greater than 17%) to overwhelm the votes of the "racially motivated white vote." Says Sirota:

[Considering] the exit polling and the fact that Pennsylvania falls squarely in the demographic Race Chasm, it is clear that those who continue to pretend race is not a major factor in this campaign are deliberately averting their eyes from a very powerful force in the Democratic primary.

Is Sirota right? Pennsylvania certainly fits the model. And exit polling data from the Keystone state clearly establishes that race was a motivating factor for a significant percentage of voters. Among whites who said race was a factor in how they cast their vote, a whopping 75% supported Hillary Clinton over Obama.

Will those numbers be the same among, say, swing white voters in Pennsylvania, in a race pitting Obama against John McCain. If so, Obama could have a hard time winning what is a must-win state for the Democrats.