If he wants to hold onto this state, which has voted for the Democrat in the last four presidential elections, Obama will have to have a much better showing than he did in the April primary, when he lost to Hillary Clinton by 10 points. In November, he will have one weapon on his side that he lacked this spring. Ed Rendell, the state's popular governor who backed Hillary Clinton in the primary, will be a key surrogate for Obama in the general election. Political experts in the state agree that Pennsylvania's demographics are more complex than James Carville's famous quip about it being Philadelphia, Pittsburgh, and Alabama in between. But Obama will no doubt have to rack up huge margins in the big cities in order to compensate for weaker support in rural areas. The key region to watch will be the Philadelphia suburbs, a heavily-populated zone with many former Reagan Democrats. McCain may be just the kind of Republican candidate who can appeal to this demographic.