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The Democratic presidential campaign has been going on for more than a year, but the real starting line is finally in sight. The Iowa caucuses are one month from today. NPR's Danielle Kurtzleben has been traveling around that state, and she reports there's a lot of room for Iowa voters to change their minds in the next month.
DANIELLE KURTZLEBEN, BYLINE: Jodi Lindberg caucused as a Republican in 2016. Now she just wants to get President Trump out of office, and so her daughter convinced her to go to a Pete Buttigieg event earlier this week. But Lindberg is still pretty far from supporting the former South Bend, Ind. mayor.
JODI LINDBERG: I'm just listening to everybody. I just anything - honestly, anything, I think, to get us out of the situation we're in.
KURTZLEBEN: This is something you learn from talking to Iowa Democrats a month from the caucuses, that interest in a candidate and support for a candidate are two very different things. Undecided caucusgoers are everywhere. Here's University of Iowa student Sophie Stover, who saw Bernie Sanders in Winterset this week.
SOPHIE STOVER: I mean, I'm considering Bernie, but I haven't really decided yet. I went and saw Pete, you know, a couple weeks ago. I really just haven't decided yet is the thing.
KURTZLEBEN: And retired teacher Kim Andresen, who saw Joe Biden speak in Anamosa.
KIM ANDRESEN: I narrowed it down. You know, I've narrowed it down to probably three.
KURTZLEBEN: This all isn't lost on the candidates. Minnesota Senator Amy Klobuchar joked about indecisive voters in Johnston on Thursday night.
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AMY KLOBUCHAR: And I know there's a lot of people that say, like, things like, oh, you're in my top three. Yay.
KURTZLEBEN: On caucus night, Iowans may get to pick more than one candidate. Iowa Democrats don't vote at the caucuses. They physically stand in a corner or sit at a table with the other people who support their candidate. And then if their candidate doesn't get enough support, they can go support someone else. That process itself could help fuel indecision, according to Ann Selzer, president of the Iowa polling firm Selzer & Company.
ANN SELZER: And it's a bit of the caucus culture that, especially on the Democratic side, you may have to change your mind in the room on caucus night. So keeping your mind open to whom else you might choose to go to is just a piece of the psychology of getting ready to go to caucus.
KURTZLEBEN: In 2016, 40% of Democratic caucusgoers said they didn't decide until the final month before the caucuses. And late deciders help make the caucuses unpredictable.
SELZER: The most common thing that we see happening - that during the days we're in the field with the final poll, the lead will change.
KURTZLEBEN: Selzer points to 2004, when Howard Dean plummeted just before the caucus while John Kerry rose. In 2008, Hillary Clinton and Barack Obama traded the lead back and forth in the final month. So by February 3, the current state of the race in Iowa could shift, even dramatically.
Right now, the Iowa race doesn't look the same as it does nationally. Most notably, Buttigieg is at or near the top of recent Iowa polls, whereas he's fourth nationally. This week, he was making the case that he wants to appeal to disaffected Republicans as well as progressives.
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PETE BUTTIGIEG: I'm meeting a lot of what I like to call future former Republicans, and I want them to know how welcome they are in this campaign we're building.
KURTZLEBEN: Any number of things could reshape this race in the final month. Fundraising totals at least show who has the most fuel. Bernie Sanders just announced that he raised $34 1/2 million last quarter, considerably more than his opponents. That kind of money could further swamp Iowa with political ads. But then, it's not clear how effective ads are. Beyond that, candidates will, of course, blanket the state with events, but those also only do so much. Selzer points to the candidate with by far the most Iowa events as evidence.
SELZER: The first is John Delaney, and he declared a long time ago. He spent a lot of time here, hasn't done him much good.
KURTZLEBEN: Klobuchar has done the second most events in Iowa, and she's still not in the lead pack of candidates. But it's not that events don't help at all. They do change some minds. After Klobuchar's Johnston events, Tim D. Huckaby from Urbandale said that he had finally decided.
TIM HUCKABY: She's somewhat of a longshot, but she's inspired me. I'm going to volunteer for her.
KURTZLEBEN: Did tonight make up your mind?
HUCKABY: It did.
KURTZLEBEN: It did.
HUCKABY: It truly did, yeah.
KURTZLEBEN: But even after a hard-fought contest, many of these caucusgoers will enthusiastically support someone new in the general election. Democrats in Iowa and elsewhere simply want to defeat Trump.
Danielle Kurtzleben, NPR News, Des Moines.
(SOUNDBITE OF LOUPO'S "I'M READY") Transcript provided by NPR, Copyright NPR.