A new poll commissioned by the League of Conservation Voters and AFSCME finds that Dem Gary Peters is leading GOPer Terri Lynn Land in Michigan by seven points, 43-37. The average of polls shows Peters leading by over six points.

Is it possible that in this particular race, climate change and the Koch brothers — whose group, Americans for Prosperity, has spent millions bludgeoning Peters over Obamacare — are hurting the Republican candidate?

The internals of the poll — which was done by respected Dem pollster Joel Benenson and hasn’t been released — show that Michigan voters view the Koch brothers unfavorably by more than two to one: 32-15. While it’s true that 33 percent have not heard of them, a total of 56 percent have heard of them, which is pretty high. A large majority finds the anti-Koch message — that Land is beholden to big oil billionaires bankrolling her campaign — convincing.

The poll also finds that 45 percent see climate change as an urgent problem, and another 13 percent see it as a problem to address in the years ahead — a total of 57 percent. And it finds 39 percent would probably or definitely not vote for someone who doesn’t believe human activity is causing climate change. Land’s position is that climate change exists, but she hasn’t, to my knowledge, clarified whether she believes humans cause it.

You should treat such internal polling with skepticism, and it’s hard to know how much this stuff matters, if at all. But here is a race where Dems are campaigning as if they genuinely do think they can make climate skepticism a liability. And when it comes to the long, painful quest of environmentalists to prove that they can turn climate change into an issue that matters in elections, the Michigan contest remains an experiment to watch.

Gary Peters is one of the few Democratic candidates this cycle who has been talking about climate change, in part because the issue matters in Michigan, due to the Great Lakes’ importance to the state economy. The Koch brothers have also taken on unique environmentally-related importance here, because of the role of a Koch Industries affiliate in a major local story involving piles of petroleum coke along the Detroit River.

Peters has called on Land to clarify whether she believes in climate science, while tying her to the Koch brothers — as a beneficiary of all that Koch cash — and localizing the Koch/environmental nexus by hammering her over the pet-coke (call it Pet-Koch?) story.

To get a sense of what that looks like, check out this ad a coalition of environmental groups has run against Land in Michigan — backed, according to the Michigan Democratic Party, by a $700,000 buy:

To be sure, climate issues may not matter much to the outcome either way. If Peters wins, it could be because this is a blue-leaning state or because Land is generally a terrible candidate.

But the fact remains that Peters has probably been talking about climate and local environmental issues — and linking the Koch brothers to them in particular — more than any other Dem Senate candidate. He was doing this back in February, when he was down in the polls. And I’m told he’ll keep doing it, now that he’s up in the polls. And if he does win, environmentalists will argue that climate change — and tying the issue to the Koch brothers — made a difference.

“The more people hear about the Koch brothers, the more concerns they have,” says Jeff Gohringer, spokesman for the League of Conservation Voters. “They could become a real liability for Terri Lynn Land.”

Greg Sargent writes The Plum Line blog, a reported opinion blog with a liberal slant -- what you might call “opinionated reporting” from the left.