CEDAR RAPIDS, Iowa — The surface at the Cedar Rapids Ice Arena was a little too rough for curling Thursday afternoon, but with four days until the caucuses, no one had time to wait for a Zamboni.

Phill Drobnick, coach of the American curling team that stormed back to win a gold medal in the PyeongChang Olympics almost two years ago, took a knee in a near-silent rink, surrounded by a couple of locals, helping them perfect their form. But really, he was there to persuade them to caucus for Amy Klobuchar.

“My goal is to talk to people, to help them to better understand who she is and what she believes in,” Drobnick said.

“I’m not someone that has been involved with politics for a long time. I’m from small-town Northern Minnesota. And I believe in order to win the presidency, we need a candidate who can win in the Midwest. . . . That’s why it felt so important to do it.”

Missing from the ice arena was the woman he was talking about, the presidential candidate and Democratic senator from Minnesota. The Senate impeachment trial has kept Klobuchar and three other senator candidates in Washington for most of the past few weeks, even as Iowa voters were closing in on a decision on whom to support in Monday’s caucuses.

The unprecedented collision between an impeachment trial and the first voting in the presidential contest forced a constant stream of campaign plans to be made and broken, for areas of the state to be written off as too hard to get in and out of during brief breaks in the trial, and for candidates to hope that their surrogates will somehow be able to build and maintain momentum that is usually driven by the candidate alone.

On Friday, as the impeachment trial reached toward an ending that appeared inevitable, it still remained unclear when the candidates would be able to escape the capital, and how much time they might have on the last campaign weekend if they did.

The wide range of surrogates — many from outside traditional political spheres — who campaigned in their stead spawned a flurry of intimate, in some cases un­or­tho­dox, campaign gatherings across the state.

Drobnick worked the state for Klobuchar. Sen. Bernie Sanders (I-Vt.) sent out filmmaker Michael Moore, actor Kendrick Sampson, the Los Angeles-based band Las Cafeteras, and a host of more traditional political representatives such as Rep. Alexandria Ocasio-Cortez (D-N.Y.). Sen. Elizabeth Warren (D-Mass.) sent out former Housing and Urban Development secretary and former 2020 presidential candidate Julián Castro.

All three — the fourth senator, Michael F. Bennet of Colorado, is focused on New Hampshire — sent close family members, too. Klobuchar’s daughter, Abigail Bressler, held hot dish parties around the state. Sanders’s wife, Jane, held town halls and coffee shop meetups and joined other surrogates at rallies. Warren’s husband, Bruce Mann, and dog Bailey held three meet-and-greets of their own in Central Iowa.

A few hours before Jane Sanders and Sampson drew supporters to a show-of-force rally in Iowa City on Wednesday night, Las Cafeteras hosted a canvas launch event on a snowy afternoon in West Liberty, Iowa. When the six-person band from East Los Angeles walked onto the tiny community center stage, the number of people in the room increased by one-third, which made seating decisions awkward for some.

“I don’t even sit in the front row at church,” a man in an Iowa Hawkeyes jacket whispered to his friend as he walked in, before settling into a seat a row back from the stage.

Instead of the usual din of Sanders events — the “Bern-ie” chants, the roars against big business — there were guitar strums and the low hum of conversation when band member Hector Paul Flores asked everyone in the audience to share where they came from with someone they didn’t know (origin stories varied from “I was born on a boat in Santa Barbara,” to “I was born in Bettendorf.”)

“It’s motivational,” said Jose Zacarias, a community leader in West Liberty who said he is stressed about his duties as precinct captain for Sanders on Monday night. “I’m a senior citizen. I need to loosen up. And the best way to loosen up is music.”

Some surrogates relied more on star power than others, most notably Bailey, Warren’s golden retriever, who trotted around Iowa with the senator’s husband to much fanfare Wednesday. Before a stop in the lobby of a student center at Wartburg College, organizers played down Bailey’s political alliance in a sales plea to students wandering by.

“Do you want to meet a golden retriever?” they asked, needing only for the interested to sign up for Warren’s contact list to do so.

Those who obliged joined about two dozen people fanned out across a lobby where puzzled students wandered through as Mann delivered a few minutes of remarks about his wife’s dedication to her cause. No throngs chanted “two cents,” as they do at the candidate’s events. No one roared when he said the word “plan.”

Other surrogates were more traditional in their advocacy — and more experienced hustling around Iowa to make their pitches. Castro became the highest-profile former member of the 2020 field to endorse another candidate when he tossed his support behind Warren shortly after ending his own campaign.

On Thursday, in the backroom of a Mexican restaurant in Waterloo near where uninterested Iowans munched on frijols and enchiladas, Castro explained to 20 or so voters why Warren is the best candidate to unite the party. He told the story of his first lunch meeting with Warren when she was on the Senate committee responsible for oversight of his work as HUD secretary. He had anticipated some small talk, he said, but didn’t get any. Warren was all business.

Later, a few voters posed for pictures with him, and Castro took questions from reporters. He said he had been to La Carreta before, during his own campaign for president.

“Of course it’s different,” Castro said. “But this is a role that I’m used to. I campaigned for Obama during his reelect in 2012. I campaigned for Secretary Clinton in 2016. So I’ve been used to both roles.”

Castro said the fluidity of the race in Iowa, where many polls show large percentages of voters have not yet made up their minds, amounts to a “great opportunity” for Warren’s vaunted Iowa campaign operation to flex its muscles and talk to as many voters as possible before Monday night.

Of course, there are plenty of other surrogates out there trying to talk to those voters, too. And some of them have curling stones.

“I’m already, you know, a willing victim,” said Charles Carroll, an Iowa City resident and member of the curling club in Cedar Rapids who got pointers from Drobnick on Thursday. “I’m kind of leaning towards Amy. But I probably won’t actually decide until I walk in the room.”