Even though it came out a bit blurry on the Stranger camera, this is my favorite picture from my experience in Iowa:

I took it last night at the caucus site I observed in Des Moines. The woman in the foreground wearing the yellow sweater is Olivia Johnson, 26, part of the huge influx of young voters who pushed Obama to victory.

I talked to Olivia during the horse-trading session of the caucus meeting—which, by the way, was held inside Grace United Methodist Church:

Where placards lined the aisles…

…and Obama supporters packed the left bank of pews…

…and observers watched, calculators at the ready for use in double-checking the complicated caucus math:

While we’re speaking of math, an aside: As Dan relayed yesterday, the numbers at my caucus site were fascinating and, it turns out, representative of what happened in Iowa as a whole. First of all, turnout at the site was up significantly, from 278 caucus-goers in 2004 to 322 this year—a small piece of the big Democratic picture in Iowa, which was record-shattering turnout, especially among younger voters like Olivia.

Second, at my caucus site Hillary Clinton almost didn’t reach first-round viability, an amazingly poor showing for a candidate who is so well-known and well-funded. Clinton needed 49 supporters to be viable, and she only had 48 until the lone Kucinich supporter in the room saw what was going on and helped the Hillary folks out. With that we headed into the second round, in which the only viable camps were Clinton (49 supporters), Edwards (53 supporters), and Obama (151 supporters). Horse-trading ensued as the viable camps competed for the supporters of the non-viable candidates, with Biden and Richardson folks conferring quietly…

…and a Hillary supporter cozying up (unsuccessfully) to a Biden backer:

In the end the Biden supporters went mainly to Obama, the Richardson supporters went mainly to Edwards, and after all the horse-trading the final second-round tally wound up mirroring the larger Iowa standings: Hillary in third with 62 supporters, Edwards in second with 72 supporters, and Obama in first with 175 supporters.

But back to where I started. It was during the horse-trading session that I talked to Olivia…

…who announced very quickly that she would not be moving from the Obama camp. She was eligible to caucus last cycle, but didn’t. This time she felt she had to—that she could not and would not miss the chance.

Olivia was in college in New Orleans during Hurrican Katrina, attending Xavier University where she majored in English. Now she works customer service at a wall-covering distributor in Des Moines. But the experience during Katrina made her see the caucuses as hugely important.

“For me, having went through Hurricane Katrina, it’s time for us to have somebody in power that’s not going to forget about their people,” Olivia told me. “Whether they’re black, white, green, purple, poor, rich, middle class—I feel like I was forgotten.”

What’s interesting here is that Clinton talked on the stump about “invisible” Americans and the shame of Katrina, while Edwards made fiery promises not to neglect the average citizen any longer. But somehow that didn’t move Olivia—or, at least, it didn’t move her as much as hearing a similar message from a voice and presence like Obama. Coming from him, change really meant something. Or, perhaps, it meant more. I asked Olivia why she thought Hillary was losing so badly to Obama at the caucus.

“It’s about change,” she replied. “It’s all about change. He’s not marketing to one specific group. He’s trying to get everybody to come together to be one America. Which is what it’s all about. We are a melting pot of all different nationalities, sexes, races, and it’s all about coming together and doing what’s right to make our country strong again.”

And Hillary wouldn’t bring about that change?

“It’s just all about that movement to get things to be better,” Olivia continued. “And yes, Hillary is a great candidate, but Obama is the one that is speaking the truth. He’s speaking about what needs to be done to bring us together so that we don’t have all of this separatism.”

So much for Edwards’s presentation of himself as the only “truth teller” in the election, and so much for Clinton’s presentation of herself as the real “change agent.” Also, notice that Olivia is speaking only in platitudes and impressions here. I heard this repeatedly in Iowa. For all the focus on issues where the candidates diverge, it seems a lot of Democrats were motivated not by policy difference but primarily by emotion and, yes, something as ephemeral as hope.

When I pressed Olivia to tell me about an issue that had pulled her into the Obama camp she told me it wasn’t about the issues. “Mostly, for me, I like his message,” she said.

Over in the Hillary crowd, William Cotton, 74, joked that maybe all of Obama’s young supporters would skip out between the first and second rounds of caucusing to grab beers and never come back, thus giving Hillary the win. They didn’t.

“It’s a surprise,” Cotton told me. “And I worry that this turnout of young people might skew the whole process for the general election.”

Well, I replied, what if young people turn out to be the pivotal force in the general election that they were on caucus night here in Iowa?

“I’m not so sure about that,” Cotton replied. “I hope that’s true. I have grandchildren that are involved in this, most of them for Obama. I would like to think it’s another Kennedy revolution. That would be my hope. I’m not sure about that, though.”