X Factor: Pittsburgh

The expected low turnout in Philadelphia today is muddying up the usual Philly-centric model for Democratic success in Pennsylvania, writes Paul Kane at the Washington Post:

Given the low-turnout projections, the Clinton and Rendell models might be rendered obsolete by the time votes are finally counted. There's one other massive clutch of votes up for grabs -- Allegheny County, home to the Steel City.

Neither Sestak nor Specter has a natural edge in this southwestern corner of the state, which is almost a six-hour drive from Philadelphia's City Hall and has much more culturally in common with Cleveland than Philadelphia. Traditionally, it has been a tough battleground, and one in which neither candidate wins by the sort of margins common to Philadelphia. Clinton won Allegheny County with 54 percent of the vote, the same margin Casey won it with in 2002.

If either Sestak or Specter can break that logjam and win by big margins in the Pittsburgh region, that could be a whole new model for victory in the Democratic primaries of the Keystone State.

Photo: WashPost