HUMBOLDT, Iowa — To Amy Klobuchar, her just-completed tour of all 99 Iowa counties proves a point: As president, she would go everywhere and represent everyone, even in the heart of Trump country.

That’s “part of my way of being,” the Minnesota senator told Iowans at a rural restaurant in Humboldt County — the final stop of her tour and a place that, like much of the lead-off caucus state, overwhelmingly supported Donald Trump in 2016. “I believe that we need someone as president who’s going to be the president for not half of America but all of America.”

Klobuchar is hoping to capitalize on caucus rules that can reward candidates who leave Democratic-heavy areas and large rallies to meet smaller groups in less populated counties. In those places, personal connections can be made over coffee or, as happened this month, over hot chocolate and convenience store breakfast pizza aboard Klobuchar’s campaign bus.

Those connections can translate into votes on caucus night, though going everywhere is no guarantee of success. Republican Rick Santorum campaigned in all 99 counties — known as the “full Grassley” after Iowa Sen. Chuck Grassley — for the 2016 election and finished close to last in the Iowa caucuses. This election, former Rep. John Delaney has already done it, but he hasn’t qualified for the debate stage since the summer.

It can be a grind.

Klobuchar started ticking off counties days after her February campaign launch and picked up the pace in recent weeks, her days on the bus sometimes going from before sunrise to close to midnight. On Dec. 22, she covered more than 1,000 miles or 1,600 kilometers on a swing that took her to events in 27 counties in under four days. A few events were held on her campaign bus because no local venues were available.

The stakes are particularly high as Klobuchar tries to catch the four top candidates — Joe Biden, Pete Buttigieg, Elizabeth Warren and Bernie Sanders — before the Feb. 3 caucuses in a state where she’s invested most of her campaign.

Klobuchar has qualified for the Jan. 14 debate in Des Moines, where she’s bound to boast about her 99-county swing and knowledge of agricultural and other issues. That’s if the president’s Senate impeachment trial doesn’t interfere with the debate and campaign.

She hopes her Midwestern background, years of campaigning for fellow Iowa Democrats and endorsements from local elected officials will give her a boost in a state where having seasoned caucus-goers and respected leaders as advocates can make a difference.

Held on a Monday night, the caucuses consist of 1,679 precinct meetings where voters must declare their preferred candidate. To have their votes counted toward delegates, a candidate must reach a viability threshold of 15% support in each precinct.

After the first vote, supporters of any candidate not deemed viable may move to another candidate. That tests the ability of viable candidates’ supporters to sway their neighbors to join their side.

“For Sen. Klobuchar the challenge is going to be making sure she’s viable,” said Chris Larimer, a political science professor at the University of Northern Iowa who researched the impact of the “full Grassley” on governor’s races. He says it can help a candidate make personal connections but “it’s just one element to a successful caucus campaign.”

Each candidate has his or her own strategy for picking up delegates. Biden is counting on being viable in every county, in part because voters know him and his support is seen as wider across the state’s geography and population.

Warren, Sanders and Buttigieg have been drawing huge crowds, particularly in college communities and other liberal parts of the state, though their campaigns say they have a statewide infrastructure to compete elsewhere, too.

None of those candidates has come close to visiting every county. But Norm Sterzenbach, a longtime Iowa political strategist who joined Klobuchar’s team as caucus adviser this month, said working to become viable in as many places as possible is smart, especially in what he sees as a five-candidate race.

He predicts Biden, Buttigieg, Warren, Sanders and Klobuchar will each miss the viability threshold in some precincts.

“The more places you can become viable, that just gets you on the board and you start earning delegates,” he said. “And so that’s why spreading this out and going everywhere is really key.” Especially, he said, for a senator from the rural state just to the north.

She “understands how to communicate to these voters,” he said. “There’s a lot of symmetry that makes it a fertile ground for her aside from the pure math.”

Sterzenbach, who helped the state party design the 2020 caucus system and previously worked for former Texas Rep. Beto O’Rourke’s campaign, said the caucuses’ smaller gatherings can have an outsized impact. In a precinct where maybe 30 voters turn out, it’s easier to connect with enough of them to be viable than it is to get 150 supporters in a caucus crowd of 1,000.

“Caucuses are about relationships,” he said. “The way that I’ve always looked at it, the closer that you can get to the candidate having a relationship with the voter, the better off you are.”

Kim Aneweer, 57, a teacher from Spirit Lake, Iowa, said she was swayed to support Klobuchar after hearing her speak Friday in Estherville, a town of about 6,000 people in a county along the Minnesota-Iowa line where over 65% of voters backed Trump in 2016.

“Today she just seems so real to me, and that’s what I’m craving, is somebody that has a decent heart and was a good person, and she sold me today,” Aneweer said. “All of her policies seem common sense to me. The fact that she’s a Midwest person — I feel like sometimes we’re overlooked here in the Midwest.”

Penny Wiersma wasn’t as convinced but said after the event that she has narrowed her choices to Klobuchar and Buttigieg. Wiersma, who at 81 said she has been a consistent caucus-goer for years, said she understands candidates can’t make it to every corner of the state because they only have so much time or money, but she appreciates when they do it.

“It feels like we’re being courted,” she said.