I just went to an Obama event near Iowa City--not far from the University of Iowa and legions of young voters rumored to favor the senator from Illinois. (The Obama campaign says there were about 900 people in attendance.) The first thing that struck me was how explicitly Obama rebutted the preparedness argument Bill Clinton made recently on Charlie Rose. Yesterday in Des Moines, Obama alluded to it only elliptically: "The real gamble in this election is playing the same Washington game with the same Washington players and expecting a different result," Obama said. Today he directly invoked Clinton's "roll of the dice" diss before making the point about the real gamble. He also delivered the lines much more forcefully than he did yesterday, and my sense is that they were the most energetically applauded of the speech. (Again, both of these things probably had had something to do with the audience.)
The second thing to note is that, unlike the other candidates, I think there are three categories of Iowans who show up at these events: Committed supporters, undecided voters, and people who just want to watch a famous speaker do his thing. I could see this last category cutting either way. On the one hand, people who show up just to soak in the spectacle may end up as supporters. As Obama strategist David Axelrod put it when I briefly cornered him, you have to draw people to your events to have a chance to close the deal, and Obama is clearly doing that. "I heard an old lady say she needed snow shoes to get here," Axelrod told me. "That's a good sign." On the other hand, many of these people have no intention of voting for Obama. If there are a lot of them--and who really knows what fraction of his audiences they constitute--they could mislead anyone trying to gauge his support from his crowds.
I talked to one man after the speech who's deciding between McCain and Ron Paul! He said he wouldn't dream of voting for Obama, but he still enjoyed hearing him speak. I can't imagine there are too many of these people showing up at Obama events. But, then, I can't imagine there are any showing up to hear Hillary or Edwards.