John Russell didn't know how many people would turn up at an organizing meeting for U.S. Sen. Elizabeth Warren's campaign last week in Sac City, Iowa (pop. 2,098). The 29-year-old former farmer and stump grinder was the headline attraction. As a rural coordinator for Warren, D-Mass., Russell has staged a string of events in Iowa's deep-red counties since April.

In the process, he has developed a strong reputation. He had 23 people show up in Mount Ayr (pop. 1,666) in Ringgold County, one of the most rural and hard-pressed in the country. Ten came in Ida Grove (pop. 2,066). Another 20 or so stopped by in Keosauqua (pop. 923).

The turnouts might not sound like much. But they are revealing when you consider that candidate John Delaney attracted just four people when he spoke in the flesh in Sac City this summer. Besides, no other campaign is doing quite what Warren is doing out here in the rural reaches. She has money, staff, a clear populist message, and she came here early and has returned often.

Warren has at least 65 staffers with a dozen offices in Iowa, says aide Jason Noble, in part because she was able to lasso much of the state's core political talent early on, including the 2016 caucus director for U.S. Sen. Bernie Sanders, I-Vt. Noble, a former political reporter for the Des Moines Register, said one-on-one campaigning is the key to winning this caucus state, where personal relationships matter and hours of time together over the previous year tend to cement commitments when the three-hour caucuses get underway on a cold night next February. "You have to generate support everywhere," he added, "because the caucuses are all about volunteers. We need people in every precinct advocating for Elizabeth Warren."

That's where Russell comes in. Earlier this year, he moved from eastern Ohio into an apartment upstairs from a biker bar in downtown Webster City (pop. 8,000), about an hour north of Des Moines. He throws down a few with the locals after a hard day of canvassing. Russell said: "They aren't shy about telling you they like Trump. But I bought a couch, table and four chairs from one of them for $25, and he helped me haul it all in. I think I can still get him."

Hailing from Trump Country himself, Russell is not afraid to engage. "I come from a place where they never see a Democrat," he said. "It's personal to me. We have to fix this face-to-face."

Twenty-two people showed up to hear about Warren in Sac City. Democratic County Chairwoman Tonya Ramsey was tickled. "How do you do it?" she asked Russell.

Russell just worked the problem. He and a colleague had spent two weekends canvassing the town, knocking on the doors of every likely caucusgoer. He papered the convenience stores with fliers announcing the meeting, both in town and at villages elsewhere in the county. He talked it up with the cashiers. Staff members e-mailed residents, then texted and called.

The 22 people who came were well-informed about all the candidates and their positions. They were picking through Medicare for All, trying to understand what it would mean for them. They were a bit long in the tooth, but that's normal for around here; only one person was under 20. Socialists they are not.

Russell talked up Warren's 2% wealth tax on those with more than $50 million in the bank, money that she would use to buy down student debt and keep rural hospitals open. Russell claims these little gatherings directly inform Warren's plans for agriculture, rural America and climate change; as voters react and make comments to what he says, Russell takes notes and shoots them to Warren's headquarters in Des Moines and Boston. "Everybody recognizes the current system isn't working for us," he said.

That sort of talk — that those at the top need to leave a share for those at the bottom — appeals to Tonya Ramsey, who works part time at a grocery store 30 miles away, having just earned her college degree online.

"They've had way more contact with me than anybody else," Ramsey said of the Warren campaign, stressing that she remains neutral.

It's a measure of Warren's strength that all 22 who came to hear Russell stuck around for two hours. By the end, a Biden supporter had agreed to another visit with Warren's staff. So did a man with a gray ponytail, who strolled in uncommitted to any candidate. If they join up, they will bring neighbors along.

And that's how caucuses — and nominations — are won: one voter at a time.

Art Cullen is editor of the Storm Lake Times in northwestern Iowa and author of the book "Storm Lake: A Chronicle of Change, Resilience, and Hope from a Heartland Newspaper." He wrote this article for the Washington Post.