The great lure of Pennsylvania for Romney, I think, is that the Obama campaign hasn't spent four years, $400 billion, and every waking moment attacking Romney and prepping get-out-the-vote operations like they have in Ohio.
Thus, the sense that PA voters are much more persuadable than Ohio voters.
The big problem with that? More of those persuadable voters are still Democratic or lean that way (1 million more registered Dems in PA), and even if Romney wins Pennsylvania, it's only because of a national sweep that would make winning Pennsylvania irrelevant in the first place, no?
On a related note, read the New York Times' great piece today on the Romney campaign's late push.
But there is a tangible sense — seen in Romney yard signs on the expansive lawns of homes in the well-heeled suburbs, and heard in the excited voices of Republican mothers who make phone calls to voters in their spare time — that the race is tilting toward Mr. Romney.
If ever there were a place where a last-ditch torrent of money could move the needle, this is it. For the last couple of months, there has been a void of presidential ads in Pennsylvania. So when Republican strategists looked for places where their money could go the furthest, they set their sights here, reasoning that a dollar spent in Erie or Altoona would have a greater impact than in a place like Las Vegas or Cleveland, where political commercials have clogged the airwaves.