Green groups are giving Democrats a real boost in their bid to keep the Senate this year—which is kind of ironic, since many high-profile Democratic candidates aren’t that great on environmental issues. In Kentucky, Alison Lundergan Grimes has gone to great lengths to out-coal Mitch McConnell. Louisiana’s Mary Landrieu has built her campaign around her reputation as Big Oil’s best friend. Kay Hagan, Mark Begich, Mark Pryor and pretty much everyone else have touted their support for the Keystone XL pipeline. Colorado’s Mark Udall is a notable exception, but the polls are increasingly grim.

The bright spot for environmentalists is, improbably, in deep-red South Dakota. Though his party gave up on the race early in the year, Democratic nominee Rick Weiland quietly took his brand of prairie populism to every town in the state. With the Republican candidate mired in a corruption scandal, the race is suddenly competitive. The top candidates—Weiland, Republican Mike Rounds and independent Larry Pressler— will debate on Thursday evening. It’s possible that Weiland could be the candidate that saves the Senate for the left.

When it comes to the environment, Weiland is running in the opposite direction from most other Democratic candidates. He doesn’t just oppose Keystone XL: he is loud about it. “There was no way, after I took a good hard look at it, I could do anything other than come out in strong opposition to Keystone, to the pipeline. I have made no bones about it,” Weiland said in an interview on Wednesday. “And, you know, it might have been easier for me to run and hide or duck and cover, but when you know the truth, I think you just have an obligation to stand up and be counted, and that’s what I’ve done.”

The way Weiland sees it, Democrats have allowed the GOP to turn support for the pipeline into a litmus test by failing to challenge the claims made by its supporters. “We haven’t had anybody in opposition with a loud enough megaphone to be able to stand up and say, ‘it’s not jobs. It’s not about energy security,’ ” Weiland explained. Surprisingly, he said he doesn’t hear that much support for the pipeline from South Dakotans.

But when Keystone does come up, Weiland simply explains how misleading the talking points in favor of the pipeline are. He understands why people have an open ear to the argument that Keystone will create jobs, but he’s quick to point out that such claims have been wildly inflated. Only thirty-five people would find permanent jobs because of the pipeline, according to government estimates. “And no one’s been able to tell me if even one of those will be in South Dakota,” he grumbled. As for the temporary jobs created by constructions, Weiland says they are “nothing more than Macy’s hiring people for the holidays. They come and go very quickly.”

Weiland is also unusual in his willingness to defend the Environmental Protection Agency. (Rounds proposes to get rid of the agency entirely.) He notes that the EPA’s proposal to regulate carbon emissions from power plants has been “controversial” in South Dakota, but faults his opponents for making “wild allegations” about the impact of those rules while ignoring the threat of climate change.

“If you want to stick your head in the sand, I guess that’s your prerogative,” Weiland said. “We’re all old enough to remember what it was like before the EPA. You could light some of the rivers and lakes on fire in this country. Do we really want to go back to that? Do we really want to trust these big corporations to do the right thing? No. We need checks and balances. We need an honest referee.”

That critique of corporate power is what links Weiland’s environmental platform to the rest of his campaign. He focuses less on the climate implications of Keystone than the fact that it’s “a big money con.” He orients critiques of the fossil-fuel industry in similar fashion, in the context of his larger message about the corrosive influence of money in politics. If that framing of environmental issues is successful in South Dakota, it should be significant to strategists trying to make climate an electoral issue throughout the country.

If Republicans take the Senate, they will undoubtedly push through a bill approving the pipeline. “That could happen as early as January,” Mike Rounds boasted in September. Many Democratic candidates have, via their loud calls for KXL’s approval, only affirmed that would be a good thing. Weiland, on the other hand, thinks that that the very real possibility that tar sands oil could soon be flowing across South Dakota will work in against the GOP in the state. (Former GOP Senator Larry Pressler, now running as an independent, also opposes KXL, which make Weiland’s effort to leverage the issue more difficult.)

Weiland’s stance on Keystone has helped him make allies in South Dakota’s Native American communities, which are strongly opposed to the pipeline crossing their lands. Last week he visited a spirit camp near Ideal, South Dakota, to show support for the members of the Rosebud Sioux tribe who have been protesting KXL there for months. All of the state’s tribes have endorsed him. If he makes it to the Senate, Weiland hopes to serve on the Indian Affairs Committee. “I’m very committed to trying to use my time in the United States Senate to improve the situation [on reservations],” he said.

Weiland also thinks he’s making inroads with people who normally vote for the GOP, particularly people whose land may be taken for Keystone via imminent domain. A bid by a Canadian corporation to mine for uranium in South Dakota’s southern hills has incited similar concern, and Weiland says he’s been talking with voters about that, too. “I think for a lot of those conservative ranchers out there that care more about their livelihood than their political party, I’m going to get a lot of votes,” he said.

“I think we win at the end of the day because we haven’t been so desperate to make what is often too much the story of accommodation to special interests instead of standing with the people,” Weiland said, when I asked if he thought reluctance to run as environmentalists was actually hurting Democrats.

“If I lose because of this issue, so be it,” he said of Keystone. “I will not lose my soul trying to get to the US Senate.”