Vermillion, South Dakota (CNN) South Dakota voters haven't elected a Democrat as governor in more than 40 years. But Republicans in Washington and in the state have recently grown concerned that could change this year.

A mix of the national political atmosphere, the uniqueness of Democratic candidate Billie Sutton and a few missteps by Republican Rep. Kristi Noem's campaign -- namely the belief that she didn't take Sutton seriously early enough -- have some Republican operatives believing that the state could surprise people in November and elect Sutton, the anti-abortion rights, pro-gun South Dakota Senate Minority Leader who was paralyzed from the waist down in a rodeo accident in 2007.

"Her and her team, a few months ago, thought this was going to be a cake walk," said a top Republican operative. "They don't now."

The operative added: "Sutton still has an uphill battle. Is it a competitive race? Absolutely. Noem's team now seems to realize that."

Noem directly denies that she didn't take Sutton seriously, but in an interview with CNN, she acknowledged that the race has been closer than she expected.

"I knew (the primary) would be hard," she said. "I didn't know about the general."

The Sutton-Noem race anchors a series of gubernatorial contests in prairie states -- namely South Dakota, Oklahoma and Kansas -- where Democrats are on offense in 2018. The Democratic Governors Association has grown confident they could flip at least one governor's mansion in the three so-called "Tornado Alley" states with authentic, local candidates who break the mold of how lean-Republican voters in each state see Republicans.

That Sutton is running a competitive race in South Dakota has also come as a surprise to some national Democrats who look at the fact that President Donald Trump nearly doubled Democrat Hillary Clinton's vote total here in 2016. In the state, however, Democrats and Republicans alike see Sutton as a formidable candidate with a singular story.

It's that crossover appeal that is apparent when Sutton campaigns. As the candidate made his way down the Dakota Days Parade here in Vermillion and later shook hands at a tailgate for the University of South Dakota Coyotes, around a dozen people used some variation of the same move to back him: They grabbed Sutton's hand, leaned down to talk to the wheelchair-bound politician and in a markedly hushed tone said they would vote for him in November.

"I might be one of those lifelong Republicans who votes for you," said a Sioux Falls businessman who declined to provide his name.

Sutton is getting used to picking up endorsements from whispering voters and those Sutton voters have distinct reasons for secrecy -- "I have too many Republican clients," said the businessman. But it's all the same to the Democrat: He just wants their vote as he looks to shock Republicans by defeating Noem, a South Dakota native who announced her run for governor almost two years ago.

Even she, though, acknowledged Sutton's candidacy is potent in the state where she was born and raised.

"He's the most talented candidate they have had in 30 years," Noem said of Sutton, who would be the youngest governor in the country if he wins. "I just don't think you can underestimate a good story. The story of his accident and his tenacity in that situation really resonates with the people of South Dakota."

Sutton is confident he will shock the political establishment and win come November, and he isn't shy about acknowledging that the accident that ended his rodeo career and landed him in a wheelchair is a big part of his success.

"It is a big part of it," he said bluntly. "It is a South Dakota story. It is about how we persevere in the face of challenges."

After rolling down the Main Street parade route, where countless voters yelled his name -- "Billie, Billie" a la the viral Bud Light ads titled "Dilly Dilly" -- he smiled and thought about how much his life changed in a decade.

"Knowing what I know now," he said. "I wouldn't change a thing."

Drain the swamp... in Pierre

Democratic State Sen. Billie Sutton

There is little in common between Sutton and Trump.

The cowboy-hat-wearing South Dakota Democrat backed Clinton in 2016, was raised about as culturally far away from New York City as one can get and had dreams of making the National Finals Rodeo in Las Vegas before a horse he was riding flipped in a chute and paralyzed him.

But there is one key similarity: Sutton's primary campaign pledge to change the status quo in South Dakota and end corruption sounds remarkably similar to the messaging that vaulted Trump to the White House two years ago.

Sutton has seized on a series of stunning scandals in South Dakota's state government and run hard as the candidate who will alter the status quo and clean out Pierre, the state's capitol.

Listening to Sutton tell it, both in person and in television ads, the message is could easily be distilled as draining the swamp.

"It's a similar message," he said. "I think that is one of the reasons I am getting a lot of support from a lot of people that supported President Trump. ... They are tired of politics as usual, they want something different, they are tired of career politicians."

The messaging has proven effective. People who meet Sutton often reference his ads, his story and his pledge to shake things up. And even Republicans who have voted for Noem for years are moved by his messaging.

"We are in a state where it is hard for a Democrat to win," Mark Knippling, a 54-year old who lives near Noem in Watertown, South Dakota, said after meeting Sutton. "But if he is anyone who can do it, he's the man who can probably do it."

Noem rejects the idea that Sutton has cornered the market on anti-corruption or change. She said she views herself as the change candidate, despite the fact her governorship would continue Republican rule.

"We have had issues in South Dakota," she said. "We know what we can trust and what we can put faith in and lately (the people of South Dakota) have struggled to put faith in their state government."

Ready to come home

It would be near impossible to know that the woman sitting in the misty cold of Hayti (pronounced Hay-tie), South Dakota, for a Friday night football game between the Hamlin Chargers and the Deuel Cardinals represented the entire state in the House.

But there sat Noem, with her mother and daughter, cheering as her son and six of her relatives helped the Chargers throttle the Cardinals in nine-man football game that night.

It's nights like this, despite the cold, that made Noem want to leave Washington and come back home. She said she was fed up with Congress and missed the place where she was born, met her husband and raised a family.

So, when she announced she was running mere days after the 2016 election, it seemed like she would be a shoe in: She was a popular, four-term congresswoman whose business background seemed like a perfect fit to run the state. But then came a tougher than expected primary and stout challenge during the general election.

"Traditionally the governor's races aren't that tough when it gets to Republican and Democrats, at least recently," she said. "So, no, I don't think anyone could anticipate the environment."

That environment is partly fueled by a deep antipathy towards Congress.

Though Noem's neighbors are eminently friendly to her -- parents from the opposing team even asked her campaign staff for lawn signs during the game -- there is a sense in 2018 that the most damning line on a politician's resume is member of Congress.

Noem rejects the idea that she is being weighed down by her time in Congress. She won the primary after all, she says.

"There is a natural distaste for Congress, but I think these races can be pretty individualized," she said. "I think it is easy for him to say that. I don't think it resonates very well, but he says it a lot."

Noem has mostly run towards Trump. But on trade, she has come out against the President whose trade wars have led to slumping commodity prices. Noem grew up growing soybeans, corn and wheat and said she still hears about the trade concerns from her brothers who continue to operate the family farm.

"Agriculture is our number one industry by far, and so the trade discussion has been tough," Noem said. "Farmers are struggling, they need a price or their commodities. It is just a tough time in rural American because of that."

Noem's campaign is clearly concerned about Sutton's standing. After not spending much on TV advertising for months, allowing Sutton to air upbeat ads about his unique story, the Noem campaign has begun to hit the Democrat.

"Democrat Billie Sutton, he's anything but independent," says a narrator in a recently release Noem ad, which seeks to tie her opponent to Clinton. "Democrat Billie Sutton, he is more like Hillary Clinton than you think."

The attack previews what will likely be the final salvo of the Sutton-Noem race: Questions about who represents the state's values.

Before heading home to serve a buffalo stew she had on the stove, Noam said she would win because voters would realize "she reflected the values of South Dakota," a not so subtle hint that Democrats can't represent the state's red population.

Sutton vehemently disagreed.

"We value honesty here in South Dakota and she hasn't been telling the truth," Sutton said. "My values are South Dakota values -- honesty, integrity and hard work. And people want something different."

CORRECTION: This story has been updated to accurately reflect that a businessman who might vote for Sutton is from Sioux Falls.