Johnson County has never had a year when more than 1,000 Democrats from a single precinct have shown up to caucus.

This year, they're preparing to break that streak.

Caucus organizer John Deeth said he expects at least 21,000 people to caucus in his county, which has about 45,000 active registered Democrats. If his projection is correct, attendance would easily surpass the 19,500 Democrats who showed up in 2016, the previous record.

In the largest Iowa City precinct, which set a record in 2016 with 935 people, Deeth is preparing for a four-digit turnout. He said he's based his estimates on past election years, coupled with the large number of Democratic candidates this year.

“One of the things you learn working on campaigns is: More candidates usually means more turnout,” said Deeth, who has been one of his party's caucus point people since 2004. “You’re more likely to find someone you click with.”

His estimates reflect a consensus among Democratic party leaders: Caucus turnout is expected to be huge. It will probably rival the 2008 record of nearly 240,000 people, which included unprecedented numbers of first-time caucusgoers, who showed up statewide to propel Barack Obama to victory. Party officials and volunteers are preparing for a massive turnout.

"We're having to resort to pretty drastic measures," Polk County Democratic Party chairman Sean Bagniewski said.

Iowa Democratic Party chairman Troy Price said he doesn't have a hard estimate for attendance statewide. But he said the large number of campaigns on the ground engaging voters, coupled with strong opposition to Republican President Donald Trump, should push attendance past that of 2008.

"I think we'll see our biggest turnout that we've ever seen," Price said.

While suburbs and other growing population centers are preparing to handle long lines and large crowds, turnout is also expected to be up in rural areas.

“From what I hear from the local people who’ve been here year after year, a lot of them are feeling the same as in ‘08," said Thaddeus Hawley, chairman of the Adair County Democrats. “There’s a we-have-to-be there, we-have-to-get-this-done type of mood."

Preparing with bigger caucus sites

Bagniewski said he’s expecting that Polk County, Iowa’s most populous county, will see more voters than ever before. He said the increased estimates have required increased creativity as the party seeks venues.

In the past, he said the county would opt for free locations, even if they were smaller than available private venues. But that contributed to some overcrowding issues in 2016, he said.

In its search for larger venues this year, the party has landed private venues like the Science Center of Iowa, Living History Farms and the Iowa Events Center.

The party could spend around $20,000 on venues alone, he said.

“We’ve never paid for this many (sites) in one year,” Bagniewski said. “We’re just going to a lot of nontraditional, bigger places.”

In Ankeny, a city that has added nearly 5,000 people since the last caucus in 2016, Bagniewski estimates he’s had to spend at least $10,000 for venues. Two precincts are expecting three times as many attendees as in 2016, he said.

►Campaigning in Polk County's suburbs

In Dallas County, one of the fastest-growing counties in the nation, chairman Bryce Smith said he's also been busy upsizing venues to prevent the space constraints that caucusgoers experienced in 2016.

That year, the county party’s budget for venues was about $2,000. Now, it's spending that amount alone on a single hotel convention center in West Des Moines. Overall, he expects to spend about $5,000.

"Our hope is that with generous donations on caucus night — they pass the hat — we will at least make our money back," he said.

Deeth projects a similar price tag in Johnson County. He said the Iowa City venue he expects to pass 1,000 voters should have enough room since it's paired with another large precinct at Iowa City High School.

►Campaigning in Johnson County

Price said the Iowa Democratic Party has been working with counties for months to identify the best locations to use as caucus sites. As of the start of January, fewer than 10 sites statewide were still searching for locations, he said.

"We feel really good about where things are," he said.

The party is working on ways to reduce long wait times, including a new online check-in option ahead of the caucuses.

Story continues below.

Numbers will be big — 'even in rural Iowa'

In Adair County, where registered Republicans outnumber registered Democrats 2-to-1, retired teacher Susie Olsen said she’s hearing more buzz around this year's Democratic caucuses.

She said she's been surprised to hear interest in the caucuses from some people she's run into at the grocery store or on the street, some of them Republicans and independents.

“It just seems like there’s a lot of interest this time around, similar to (Barack) Obama in 2008,” said Olsen, who serves as secretary of the Adair County Democrats. “(Trump) certainly has a lot of support in Adair County, no doubt. But some Republicans think it might be time for a change.”

Patty Judge, former lieutenant governor and former Iowa secretary of agriculture, said she's expecting huge turnout in rural southeast Iowa. Many of the top candidates have released comprehensive rural policies and plans — a shift from previous caucus cycles, she said.

“I think caucus night is going to be a Democrat night, and there will be huge numbers, even in rural Iowa,” she said.

Price agrees that interest in this cycle should elevate turnout around the state, including in small towns.

Hawley, the Adair County Democrats chairman, said he believes a strong showing will be important in a cycle when Iowa’s first-in-the-nation status has been criticized, including by presidential candidates.

“If even in the small rural areas you have great turnout numbers — there’s so many reasons to keep Iowa as first in the nation," he said.

Voter guide: Don’t have a lot of time? Find FAQs on the key issues, where the candidates stand and more to make your vote matter.

After 2016 record, GOP prepares for lower turnout

As Democrats brace for record numbers, Republicans are expecting much lower numbers coming off the party's 2016 record high, when more than 180,000 people turned out.

While there are no solid projections, this year's turnout is expected to be similar to the few thousand who showed up in previous years when an incumbent Republican president has run for reelection, said Republican Party of Iowa communications director Aaron Britt.

"For us it's a lot like a midterm year," he said.

Neither former U.S. Rep. Joe Walsh of Illinois nor former Massachusetts Gov. Bill Weld, the two Republican challengers, have spent much time in Iowa to win support. But Britt said the challengers could motivate Trump supporters to show up to caucus for the president.

The Iowa Republican Party did not scrap its traditional caucus night straw poll, even as some other early states canceled their caucuses and primaries as a show of solidarity with President Trump.

"We felt like as a first-in-the-nation caucus state, we wanted to show the rest of the country that we’re able to put on a fair, successful caucus," Britt said. "(It's also) a good way for President Trump to show he still has a strong backing."

Register reporters Katie Akin, Shelby Fleig and Kim Norvell contributed to this article.

Ian Richardson covers Ankeny and Altoona for the Register. Reach him at irichardson@registermedia.com, at 515-284-8254, or on Twitter at @DMRIanR.

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