When it was announced that Oklahoma Attorney General Scott Pruitt was Donald Trump’s pick to head the Environmental Protection Agency, Maine’s U.S. Sen. Susan Collins reportedly said, “I don’t know who he is. I truly know nothing about him or his views. I didn’t even know his name.”

It wouldn’t take Collins very long to learn that Pruitt has touted himself as “a leading advocate against the EPA’s activist agenda.” And that’s no idle boast — Pruitt has repeatedly sued the agency he might soon lead. His record of protecting industry polluters and opposing sensible protections for public health make him a terrible choice to lead the EPA.

Sen. Collins has carefully cultivated a reputation as the most environmentally conscious Republican leader in Washington. The Pruitt pick demands that she speak out in opposition.

Pruitt has been on the wrong side of almost every issue touching on public health and environmental protection. He wrote last year that the science connecting human activity to climate change is “far from settled” — which is utterly false.

He has opposed the EPA’s ability to regulate carbon, an essential tool in the fight against climate catastrophe. He has also opposed common sense regulations to regulate factory farm pollution, and has done nothing to protect Oklahomans who are dealing with frequent earthquakes linked to oil and gas fracking.

He has tried to thwart efforts to regulate air pollutants such as mercury and arsenic, and one of his lawsuits against the EPA sought to overturn a rule to protect streams and wetlands.

With a record like that, it is no surprise that Pruitt has enjoyed tremendous financial support from the polluting industries counting on him to lead the EPA. He has even literally carried water for his industry backers. In 2011, in his capacity as attorney general, Pruitt sent a sternly-worded letter to the EPA complaining that the agency was wrong about the air pollution caused by gas drilling in Oklahoma. But the letter was not actually written by Pruitt at all; it had been drafted by lawyers from one of the gas companies doing business in his state.

For years, Collins has enjoyed a reputation as the Senate’s most environmentally-friendly Republican. Unlike Pruitt, she accepts that climate change is real, and caused by human activity. She knows the unique threats to Maine’s environment and economy; everything from tourism to our lobster industry is at risk from climate catastrophe. Not to mention the fact that Maine faces an urgent drought problem right now.

It is not unusual for there to be partisan disagreements over agencies such as the EPA. But Trump’s decision to nominate one of the agency’s most persistent antagonists, who has built a political career backing the very industries the EPA must regulate, is astonishing — though perhaps not surprising.

In one of the Republican presidential debates, Donald Trump vowed to “get rid” of the EPA. He can’t really say, “You’re fired!” to an entire government agency. But choosing Scott Pruitt might be close enough. Pruitt’s appointment would be a disaster for every person in the United States who drinks water or breathes air.

Sen. Collins has enjoyed the support of state environmental organizations for many years, and she has a record of standing up to fossil fuel-friendly lawmakers in her own party. Now she must demonstrate the courage to say no to the climate denier Trump wants to put in charge of the EPA.

Nisha Swinton is a senior organizer for Food & Water Watch, based in Portland.