The three-term congressman is in a tough race against obstetrician Roger Marshall ahead of the Republican primary Tuesday. Their battle in the 63-county 1st District of western and central Kansas is the state’s most notable contest this year—and some tea party conservatives fear it could resonate nationally if Huelskamp loses.

Marshall argues that the sluggish agricultural economy is the biggest concern for a district where wheat fields flow to the horizon and cattle far outnumber people. And a key issue is Huelskamp’s loss of the state’s near-automatic seat on the House Agriculture Committee late in 2012 after disputes with GOP leaders over farm legislation and measures for keeping the federal government operating.

“In the real world, you have to figure out how to work with other people that have different values, different views,” said Jim Schmidt, a 40-year-old Junction City-area farmer and father of four. “My goodness, if you’re married and you have children, you understand life is a compromise.”

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While many Republicans consider Huelskamp obnoxious, many also admire his anti-establishment streak. His supporters contend he gives his conservative, safely Republican district a strong voice against President Barack Obama, fellow Democrats and GOP leaders who are too soft on them.

“We can trust him to do the job we need him to do in Washington and not give in to the political pressures,” said Mary Reader, a 44-year-old Manhattan nurse and mother of eight, said after a Huelskamp town hall meeting in Junction City. “Consensus usually means you’re losing your values.”

Supporters of both candidates expect a close race. There’s no Democratic candidate — something that’s happened regularly over the decades — but Alan LaPolice , an educator and farmer from the small north-central town of Clifton, is poised to run as an independent. LaPolice lost a closer-than-expected race to Huelskamp in the GOP primary in 2014.

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Huelskamp, 47, grew up on a farm near the small town of Fowler, in southwest Kansas, and served 14 years in the Kansas Senate before winning the congressional seat in 2010. He still enjoys strong support from the tea party as well as social conservatives — and has an endorsement from Senate Agriculture Committee Chairman Pat Roberts, a fellow Kansan.

But Marshall, 55, from the central Kansas community of Great Bend, has endorsements from the Kansas Farm Bureau, Kansas Livestock Association, National Association of Wheat Growers, and U.S. Chamber of Commerce.

Huelskamp has said repeatedly that with John Boehner’s departure from Congress, he’s likely to regain a seat on the Agriculture Committee held by Kansas for decades, and he notes that fellow Republicans elected him to the GOP committee that makes assignments. Marshall and his supporters are skeptical, arguing that Huelskamp has alienated too many colleagues to regain a plum assignment.

“Because Huelskamp’s reputation is so bad, he has no voice,” Marshall said during a recent interview in between campaign stops in Emporia. “He has no influence on the process.”

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Both candidates have raised more than $700,000 for their campaigns, but Marshall has loaned his campaign more than $280,000. Independent groups have spent more than $2.5 million on the race, favoring Marshall by a wide margin going into the final week of the primary campaign.

Huelskamp, who celebrated when Boehner was forced to step down last year as U.S. House speaker, tells voters that the GOP establishment is trying to get rid of him.

“Are you going to let someone in Chicago or London or Washington, D.C., tell you how to vote?” Huelskamp said near the end of his Junction City town hall meeting.

Locked in a contentious race, Huelskamp appeared at town hall meetings recently with several conservative GOP congressmen, including Rep. Steve King, of Iowa.

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“You cannot allow a message to come out of Kansas that says, ‘We’re going to embrace the establishment wing of the party,'” King said near the end of an event in St. Marys, northeast of Topeka, at Patriot Outfitters, a guns-and-hunting gear seller that has in its offices a large painted statue of the Virgin Mary with arms outstretched.

Though Marshall shied away from the idea, Rich Felts, president of the Kansas Farm Bureau, said the race is a referendum on the tea party.

“At some point, if you don’t do what we do in politics and compromise a little bit, you become an obstructionist to the system,” Felts said.