The cruelty and the idiocy of Donald Trump’s presidency does not chiefly lie in his tweets or even his words. Trump the performer is ridiculous, but that’s the clown show that keeps many of us either terrified or entertained – the real harm is elsewhere, away from the blaring headlines.

Trump has been most destructive in his willingness to carry out an unabashedly rightwing policy agenda. Most Republicans competing for the nomination in 2016 embraced their party’s total capitulation to the fossil fuel industry, denying the existence of climate change and promising to shred Environmental Protection Agency (EPA) regulations. This is a central threat to America’s future: a major, powerful political party rejecting science itself.

This week, the Trump administration said it would weaken federal clean water rules designed to protect millions of acres of wetlands and thousands of miles of streams from pesticide runoff and other pollutants. This proposal would not just undo Obama-era regulations but chip away at protections instituted under the late George HW Bush, perhaps the last major Republican to pay even lip service to the environment.

The Obama era rule was designed to limit pollution in about 60% of the nation’s bodies of water, protecting sources of drinking water for about a third of the United States. Federal authority was extended to limit pollution in large bodies of waters and smaller bodies that drain into them, like streams and wetlands. Rural landowners complained about the government regulating how much pollution from chemical fertilizers and pesticides could seep into water on their property.

Real estate developers and owners of golf courses attacked the water regulations too, and cheered the news that Trump, a fan of both real estate development and golf, was delivering on a campaign promise. The protection of our water, they figure, shouldn’t interfere with business.

Not only will it soon be easier for pollution to seep into our waterways, if a developer finds a wetland is in the way of a money-making opportunity, the habitat can be paved over altogether. Wetlands adjacent to a major body of water will warrant federal protection. The rest are fair game.

The job of the next president will be to undo the damage Trump has wrought

Environmentalists are rightfully horrified and fearful of what’s to come. It’s not just clean drinking water the Trump White House has disregarded. Proposals have circulated to weaken regulations on planet-warming emissions from power plants, oil rigs, and cars. Trump is trying to speed new drilling at the Arctic national wildlife refuge. As climate change accelerates and the planet hurdles ever closer to an existential crisis, Trump went to a United Nations conference to tout the benefits of fossil fuels.

The current administrator of the EPA, Andrew Wheeler, used to spend his time lobbying against environmental regulations on behalf of coal magnate Robert E Murray. He was chief counsel to Senator James Inhofe of Oklahoma, a proud denier of climate change.

Democrats hoping Trump is impeached, indicted or somehow toppled before 2020 should understand even such farfetched scenarios won’t change the status quo. Trump has surrounded himself with people who care far more about the sanctity of fossil fuel profits than the safety of the American people. They worship at the altar of nihilistic capitalism. Mike Pence won’t save you.

For 2020 and beyond, climate justice will have to become the most animating issue for Democrats – not because it’s a “winning” argument, though it is, but because the future of the planet depends on it. This is why Alexandria Ocasio-Cortez occupied Nancy Pelosi’s office to force support for a “Green New Deal”. We are left with no other alternatives.

The job of the next president will be to undo the damage Trump has wrought. There will be much handwringing about the shattering of democratic norms, but the real work will be in doing whatever we can, in the little time we have, to avert a true climate catastrophe.