INDIANOLA, Iowa — Daniel Hyer drove eleven hours from Columbus, Ohio, to attend a rally with Sen….

INDIANOLA, Iowa Daniel Hyer drove eleven hours from Columbus, Ohio, to attend a rally with Sen. Bernie SandersBernie Sanders2020 Dems celebrate Black History Month Critical Iowa poll scrapped over apparent coding errorMichael Moore: Clinton comments about Sanders ‘divisive,’ ‘cruel’ and ‘a lie’MORE (I-Vt.) in this small college town just south of Des Moines. In the days leading up to the Iowa caucuses Monday, he and the six friends sharing his Airbnb will knock on doors, call voters and sit through a training that will teach them how to corral Sanders supporters at a precinct in the area.
For all the millions of dollars spent on television advertisements and mail pieces, survey research and office space, it is volunteers like Hyer, and the organizations they represent, who can make the difference between a strong performance that propels a candidate forward into subsequent primaries and a weak showing that dooms a candidate to the footnotes of history. 
We know how important it is, Hyer said.
The leading Democratic campaigns have spent a year building robust armies of volunteers across Iowa, volunteers they will deploy to caucus sites with instructions to build and hold coalitions of supporters in each of the states 1,700 precincts. Those volunteers are armed with talking points meant to persuade supporters of other candidates who might not meet viability thresholds to switch allegiances after the initial round of voting takes place.
The caucus is all about organizing, and weve taken organizing very seriously, I think more seriously than any other candidate in the state, said Misty Rebik, Sanderss Iowa campaign director.
Sanderss campaign will have at least one precinct captain at every caucus site. At locations where big crowds are expected, they plan multiple leaders, Rebik told The Hill. Former South Bend, Ind., Mayor Pete ButtigiegPeter (Pete) Paul Buttigieg2020 Dems celebrate Black History Month Critical Iowa poll scrapped over apparent coding errorIowa voters play pundit with decision time at handMOREs campaign has trained about 5,500 precinct leaders in Iowa, a spokesman said. 
Other campaigns declined to detail their organizing plans ahead of Mondays caucuses. But in such a tight race, as polls show four and possibly five candidates with a chance to win the first delegates in the march to the Democratic presidential nomination, the quality of the teams they have built will matter on a cold weeknight, when voters have to stand for hours among friends and neighbors, publicly declaring in some cases several times which candidates they support. 
If you dont have people on the ground that know Iowa, then youre at a disadvantage, said Rob Sand, Iowas Democratic state auditor. You could literally lose people because you dont have a precinct captain.
Caucus calculus is confusing enough on its face. Candidates must receive 15 percent of the vote in an initial alignment in order to stay viable. Supporters of those who do not reach the viability threshold are then free to migrate to a viable candidates team. Speeches ensue, arms are twisted, friendships tested, and hours can tick by.
Organization is so important because people you respect, their neighbors, are able to convince [voters] and then its really important to get them out to the caucus and then to organize them at the caucus, to try and get the maximum delegates, said Tom Miller, Iowas Democratic attorney general, who backs former Vice President Joe BidenJoe Biden2020 Dems celebrate Black History Month Critical Iowa poll scrapped over apparent coding errorMichael Moore: Clinton comments about Sanders ‘divisive,’ ‘cruel’ and ‘a lie’MORE.
A strong and dedicated volunteer base is likely to matter even more this year, with so many candidates hovering just above or below the viability threshold. A huge percentage of Iowa Democratic voters have held off on deciding who they will support, conscious both of the wide array of options before them and the pressure they feel to choose a candidate who can beat President TrumpDonald John TrumpCoronavirus death toll rises to 304 in ChinaMichael Moore: Clinton comments about Sanders ‘divisive,’ ‘cruel’ and ‘a lie’Palestinian Authority cuts security ties with US, Israel following Trump peace plan announcementMORE in November.
Iowans have really had ample opportunity, and theyve seized it, to meet a lot of the candidates, a lot of them multiple times, said John Norris, a former state Democratic Party chairman who is backing Warren. The angst over the decision and electability is just crazy. 
In some cases, campaigns make mutually beneficial deals to cooperate or align on caucus night. If one candidate does not reach the 15 percent threshold required to win a delegate in a given precinct, his or her precinct captain will encourage supporters to migrate en masse to another candidates team. 
In 2008, supporters of then-Sens. Barack ObamaBarack Hussein ObamaMichael Moore: Clinton comments about Sanders ‘divisive,’ ‘cruel’ and ‘a lie’Iowa voters play pundit with decision time at handThe Memo: In Iowa, how much change do Democrats want?MORE and John Edwards crafted an alliance to help deny delegates to the national front-runner, Hillary ClintonHillary Diane Rodham ClintonMichael Moore: Clinton comments about Sanders ‘divisive,’ ‘cruel’ and ‘a lie’Amid Clinton attacks, Sanders tries to move past 2016Is Hillary Clinton angling to become vice president? MORE. 
Charlie Jordan, who will captain a precinct for Biden in Des Moines, said Thursday she had already received her marching orders. She said Bidens coalition would be a natural home for supporters of Sen. Amy KlobucharAmy Jean Klobuchar2020 Dems celebrate Black History Month Iowa voters play pundit with decision time at handSunday shows preview: Lawmakers prepare for final vote on impeachment; 2020 Democrats make final push before Iowa causesMORE (D-Minn.), who is hovering just under the viability threshold in most public polling. 
You look at the weak ones, Jordan said, a hint of mischief in her eye. Her supporters would be fantastic for us, but I really think shes going to have a fantastic turnout.