For the next eight months, America will be awash in campaign ads funded by Americans for Prosperity, the political action committee backed by Charles and David Koch. With a combined net worth of $80 billion, the Koch brothers have already funneled more than $30 million into congressional races. As of February, AFP had spent more money on ads attacking North Carolina Senator Kay Hagan than Democratic groups had spent on all Senate races in the country combined.

The pushback from Democrats thus far has consisted mostly of efforts to debunk the lies spread by the Koch TV spots on Obamacare—pointing out, for example, that the Michigan woman who claimed it has made her leukemia treatments “unaffordable” will in fact save at least $1,200 a year under her new plan. The Kochs’ election strategy is a sort of bait-and-switch, since their stake in public policy is, in fact, only tangentially related to healthcare. Anti-Obamacare messaging is part of a larger campaign against government regulation that threatens the Kochs’ bottom line—most critically, in response to climate change. “We have a broader cautionary tale,” Tim Phillips, the president of AFP, told The New York Times. “The president’s out there touting billions of dollars on climate change. We want Americans to think about what they promised with the last social welfare boondoggle and look at what the actual result is.”

The Kochs’ investments in fossil fuel include petrochemical complexes and thousands of miles of pipeline and refineries in Alaska, Minnesota, and Texas, an empire that emits over 24 million tons of carbon pollution every year, about as much as 5 million cars. Thanks to a recent investigation by the International Forum on Globalization, we now have confirmation of what was long suspected: the Kochs are one of the biggest investors in Alberta’s tar sands, with a Koch subsidiary holding leases on 1.1 million acres of land in the region, giving them a major stake in the approval of the Keystone XL pipeline—despite their insistence otherwise.

To protect their interests, the Kochs have long sought to discredit science and government. In Congress, more than a third of the House and a quarter of the Senate have signed a Koch-backed “no climate tax” pledge, promising to vote against any spending to fight climate change unless it’s offset by an equal amount of tax cuts. When Republicans took over the House in 2010, seventy-six of the eighty-five freshmen had signed the pledge; fifty-seven had received campaign contributions from Koch-affiliated groups. Since then, the House has voted to bar the Environmental Protection Agency from regulating greenhouse gas emissions and has repeatedly cut its budget. If the GOP retakes the Senate this year, the party will be even more indebted to the Kochs.

Environmental groups plan to provide cover for candidates under fire who favor “clean energy and clean air policies.” But many Koch-targeted Democratic senators—including Mary Landrieu of Louisiana, Mark Begich of Alaska, Mark Pryor of Arkansas and Mark Warner of Virginia—support the Keystone XL pipeline and some have opposed the EPA’s attempts to regulate carbon pollution. President Obama talks seriously about climate change, and his EPA has made some good moves, but he’s also hailed the domestic oil and gas boom as if “energy independence” could justify climate destruction. The answer to our planet’s predicament, at least for now, is not going to come from the Democratic Party. Nevertheless, it is crucial for the climate movement to expose the efforts of the Kochs and the other fossil fuel giants to hijack the democratic process for their own dirty ends.