The Obama tour of Philadelphia, which includes North Philly, Mayfair and Germantown, is concluding with a massive rally at 52nd and Locust in West Philadelphia, The crowds have been large and enthusiastic throughout. but this one is truly immense, covering several blocks of 52nd. As the motorcade goes through the streets, people jump and wave in excitement. This is not something you see everyday, even covering a presidential campaign.

As I said before, Obama has never had a day like this, with four stops in succession in different parts of one city. He hasn't spent a whole lot of time campaigning in the black community. But he's made an exception today, and it's not surprising that Philadelphia is the place. We don't often think of it this way, but Philadelphia is the most important big city in a presidential election. The cities that are bigger -- New York, LA, Chicago, Houston and Phoenix -- all are in states that aren't battlegrounds.

Gov. Rendell and local Democratic leaders are ecstatic. "No question," Rendell said, "the mayor [Michael Nutter] and I were clamm\oring to get him into Philadelphia, to get him to do this kind of day. We had a little bit of a tug with [Obama headquarters] in Chicago but I think Chicago's happy now...Think of the buzz this will create when people say they saw Barack Obama in Vernon Park [Germantown] or on 52nd Street."

An Obama campaign spokesman said that the campaign never resisted the idea. And yes, he said, the campaign is happy.

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