Maybe it’s the crisp fall weather. Maybe it’s that the top local football teams are playing out of state or not at all. But whatever the reason, this is Pennsylvania Weekend in the 2008 presidential race. And it is the last time, as I see it, that the campaign will focus intensively on my own Keystone State.

Why? Because, barring some as of now unforeseeable “October surprise,” Barack Obama and Joe Biden are about to put Pennsylvania away--frustratingly out of reach once again for Republicans who have been yearning to take the state for the first time in 20 years.

It’s almost certainly not going to happen.

This weekend, all of the presidential players are where they should be: Gov. Sarah Palin and Sen. John McCain in the West and the rural “T” (the wooded Appalachian hills and coal towns between and surrounding Pittsburgh and Philadelphia), while senators Obama and Biden work the East, especially the big, vote-rich suburban counties near Philly and, in Biden’s case, up in his famous first hometown of Scranton with the Clintons in tow. In the campaign’s last days, the strategy is as plainly visible as your travel schedule.

It has been the GOP’s hope--and Karl Rove’s dream--to win Pennsylvania by focusing on cultural issues (abortion, gun control, prayer in schools, evolution and the like) in the “T” and in the Roman Catholic-dominated old mining and mill towns of Western Pa. It is a strategy that helped produce GOP victories for Ronald Reagan and Bush the Elder, but it hasn’t worked since 1992, when Bill Clinton took the state and established a close working relationship with the current governor, Democrat Ed Rendell of Philly. Rendell was for Hillary in the primaries, but that was bound to change once Obama wrapped things up and shrewdly chose Biden (a semi-Philly guy, being from Scranton and nearby Wilmington, Del.) as his running mate.

The easy explanation for why Obama is ahead by 14 points in the average of state polls in Pennsylvania is that the collapsing economy has trumped culture-war issues. As blue-collar workers watch the collapse of the auto industry, so the story goes, the deer hunters and anglers in economically depressed Appalachia forget culture and remember their Democratic Party roots.

But the “Deer Hunter” explanation is dead wrong. The real reason why Obama is so far ahead is that there is a new Pennsylvania--a new Pittsburgh having joined what became a new Philly long ago. The economy is not devastated in Pennsylvania right now any more than, say, Massachusetts--with which it now shares many characteristics. Pittsburgh is a college and research town; the Philly suburbs, once the home of the old GOP establishment, long ago took their tolerant attitudes into the Democratic Party.