Her Republican opponent in the state's US Senate race, Rep. Kevin Cramer, has even run a television ad saying as much.

"I like Heidi. Who doesn't like Heidi," said retired Air Force Reserve Lt. Col. Patricia Traynor in an ad for Cramer.

But, Traynor adds, "I don't like the way she votes in Washington."

That's the dynamic in North Dakota's Senate race. Heitkamp may be personally liked in the state, but the Democratic Party isn't. President Donald Trump won North Dakota in 2016 by 36 points and remains hugely popular here.

The state is critically important for determining Senate control in the 2018 midterm elections. If Heitkamp loses in November, the path for Democrats retaking the chamber becomes increasingly difficult.

Polls put Heitkamp behind Cramer. And with one month to go until Election Day, "North Dakota nice," as it is called here, has taken a backseat to bare knuckles politics.

The latest flashpoint in the race was the battle over the confirmation of Supreme Court nominee Brett Kavanaugh. Heitkamp, who was one of only three Democratic senators to vote for Trump's first Supreme Court nominee Neil Gorsuch, voted against Kavanaugh after he faced accusations of sexual assault.

For a candidate who has touted her ability to work with the President, the move was politically risky.

Heitkamp was quick to cut a TV ad explaining her vote as a matter of conscience, politics be damned. And though she knows it could hurt her, Heitkamp told CNN she hopes voters see it as another example of her independence.

"I reminded them this is what I do. I don't take shortcuts," she said. "I've taken some tough votes in the Senate. I've taken some tough votes that Democrats haven't liked in the Senate. I've taken some votes that Republicans haven't liked, but at the end of the day, you have an obligation to do the right thing as you see it, and I think that's what's missing maybe a little bit in politics today."

Cramer calls himself the most surprised person in America by her no vote.

"She'd been building her entire campaign, really her entire brand, as the bipartisan senator from North Dakota that reaches across the aisle, works hard to be in sync with Donald Trump when it's politically right and not when she thinks it's politically right, to the point where you know she said, 'I will always be with President Trump when he's with North Dakota,'" he said.

"The Kavanaugh vote blew all that out. To me, she had more to lose there than had she voted for him. Had she voted for him, she would have maintained where she was now, except probably would have lost some of her base. Her base is much smaller than the pro-Kavanaugh base in North Dakota," Cramer said.

North Dakota may be seen as a reliably ruby red state, but it was actually only eight years ago that this Great Plains state was represented by two Democratic senators: longtime incumbents Kent Conrad and Byron Dorgan.

What's changed? Remarkably, Cramer and Heitkamp gave the same answer to that question: The Democratic Party.

"The Democratic Party has changed a ton, and that shift of the Democratic party to the far fringes of the left ... it's made it very difficult for Democrats," Cramer said.

More significantly, Heitkamp too said she worries about the way her party is headed and what it means for the fate of moderates like her.

"I think that what's happened is the perception of the Democratic Party has changed that they have gone way too far to the left, and people don't trust that," Heitkamp said.

Watching Heitkamp on the campaign trail, the happy, easy demeanor she is known for is still on full display. She talks policy, family and politics with everyone and anyone -- from a parade route to an Oktoberfest celebration.

She knows political strategists in both parties in Washington are writing her off as a goner in November. She takes heart in reminding people, and perhaps herself, that it was a squeaker when she won her first term six years ago by less than one percentage point.

"People would say that, 'well it's tougher right now.' I don't know that that's true. I still think I have to make the case for what I'm going to do," Heitkamp said.

"What's different this time is I have a record and some of the votes I've taken," she continued. "Obviously the Kavanaugh vote, people will judge and say, 'Well I didn't think she was going to do that,' or, 'I'm glad she did that,' but at the end of the day I hope they judge me the same as a person and as somebody who has principles who wants to do the right thing."

Already a political battlefield

Well before the Kavanaugh vote, Heitkamp was considered the most endangered Democrat in the US Senate. Her challenge was made a whole lot harder when Trump, who had said nice things about her, worked with her and even talked to her about a Cabinet post, talked Cramer into running against her.

Cramer, currently serving as this thinly populated state's at-large congressman, was open about the fact that he did not want to run against Heitkamp.

"No, I did not. I still don't," Cramer told us with a laugh.

The President twisted his arm, telling Cramer his resistance "disappointed" him and implored Cramer to think more about the country than himself.

"I did not want to run, and yet since I made a decision to do it, I've never looked back. I've never regretted it," said Cramer.

Convincing Cramer -- largely viewed as the best candidate they had to beat Heitkamp -- was an important part of a GOP effort to grow their slim Senate majority.

As for Democrats who are bullish about a blue wave being so strong it could even potentially mean taking the Senate, they see keeping North Dakota as key to that.

In a political world where Democrats nationally are loathe to say anything positive about the President, it is striking to hear Heitkamp hit a very different note. She works hard not to alienate constituents who voted for her six years ago, and also voted for Trump in 2016.

"The President remains popular in North Dakota," said Heitkamp, who has spent almost two years aggressively working with the White House on areas where they agree, including energy issues. "I think that that makes sense because a lot of the agenda items that he's pursued, especially on deregulation have been incredibly popular. Those are things I share with him."

A wildcard: Trump trade policy and farmers

Where Heitkamp breaks with the President is on one of his signature issues -- trade policy. Much of her focus right now in the Senate, and in her urgent quest to get re-elected, is on farmers.

In retaliation against Trump's new tough on China trade policy, Beijing has imposed its own new tariffs on agriculture products grown in red states like North Dakota.

Soybean farmers in particular, many of whom sell exclusively to China, are feeling economic pain as they harvest the crop.

Heitkamp invited us to visit the farm of Tom Brosowske in Wyndmere. Standing next to a field of soybeans as far as the eye could see, he said he has already lost $100,000, and fears losing more. With China out, there is no market to buy his crop. Storage is expensive, and soybeans don't last as long as other crops like grain.

Cramer, along with the President, is urging farmers to be patient, saying that shaking things up is crucial for the long term goal of rebalancing trade with China.

Brosowske says the big concern he and other farmers have is the lack of an endgame.

"How is it going to work out? I haven't heard a plan," he said

Heitkamp is delicately hoping some of the President's natural base turns on him as the economic pain from his policies hit close to home.

"This is the 13th week with no orders out of the Pacific Northwest and you know you want to be patriotic and you want to do the right thing but you wonder, why am I suffering so that Apple can grow bigger, so that tech can get the advantage of what we're doing," Heitkamp asked rhetorically.

As for Cramer, he says he tried to stop the President from imposing tariffs on China for fear of retaliation against North Dakota farmers, but he lost.

"That said, once the President sets a strategy, a global strategy, I think it's better if we get behind him, unify, and win a trade war fast rather than undermine the entire process," said Cramer.

He is playing the patriotic card, and even suggesting things could change after Election Day, despite having no proof at all that could happen.

"I think China will be at the table of settling fairly shortly after the election, to be honest with you. In the meantime, they're going to try to use political pressure where they can. Yes, it's a real hurt. What I've tried to impress upon the President many times is that short-term pain for a farmer can be the end of his career, depending again on his personal circumstances," said Cramer.