Across the United States on Presidents’ Day, thousands of Americans rallied in opposition to Donald Trump’s lawless abuse of the power to declare a national emergency. Organized by MoveOn, Indivisible, and immigrant-rights groups such as Voces de la Frontera, the rallies in cities and small towns offered another opportunity to declare Trump to be the worst president ever.

Each day, Trump does more to stake claim on the “worst-ever” title. It’s not as if he lacks competition. But Trump keeps distinguishing himself, not merely by what he does but also by what he discourages the rest of us from doing at an urgent moment in our history.

The way to measure presidents is not always by the purposeful and explicit harm that they do, although it is certainly appropriate to consider the damage done by crude bigots such as Andrew Jackson and Andrew Johnson, awful compromisers such Rutherford Hayes, lawless shredders of the Constitution such as Richard Nixon, and assorted imperialists, militarists, and warmongers. Another way to measure terrible presidencies is according to the good they fail to do—or that they actively avert.

By this measure, presidents who might otherwise be accorded credible places on the list of the 45 chief executives who have served since 1789—those who failed to address the sin of slavery and the mounting threat of Civil War, those who ignored economic turbulence and allowed downturns to become depressions, those who accepted the erosion of civil liberties when they most needed protection—may be judged deficient.

No president is perfect, of course. Even the well-regarded are often exposed upon examination as disappointments because of flawed choices and deficiencies of courage. But those who refuse to respond to crises merit special scorn. And those who discourage the rest of us from responding invite an even more severe contempt.

By these measures, Donald Trump is in the process of placing himself at the bottom of those lists of presidents that are prepared each February, as the country pauses for the disappointing half-holiday we dub “President’s Day.”

On the day before this year’s Presidents’ Day, the front page of The New York Times Sunday Review section was devoted entirely to the message: “TIME TO PANIC: The planet is getting warmer in catastrophic ways. And fear may be the only thing that saves us.” The striking essay by David Wallace-Wells, the author of the forthcoming book The Uninhabitable Earth: Life After Warming (Tim Duggan Books), reminds us that “In October, the United Nations Intergovernmental Panel on Climate Change released what has become known as its ‘Doomsday’ report—‘a deafening, piercing smoke alarm going off in the kitchen,’ as one United Nations official described it—detailing climate effects at 1.5 and two degrees Celsius of warming (2.7 and 3.6 degrees Fahrenheit). At the opening of a major United Nations conference two months later, David Attenborough, the mellifluous voice of the BBC’s ‘Planet Earth’ and now an environmental conscience for the English-speaking world, put it even more bleakly: ‘If we don’t take action,’ he said, ‘the collapse of our civilizations and the extinction of much of the natural world is on the horizon.’”

All true. And this is not the only call for panic. The Guardian Weekly cover just featured the “I Want You to Panic” call by 16-year-old Swedish student Greta Thunberg, which has inspired a global “pull the emergency brake” protest movement by young people who are no longer content to wait for adults to act against climate change.

But Donald Trump is aggressively and actively not panicked. He says so. And his statements steer Americans away from a sense of urgency regarding an issue that demands an all-hands-on-deck response.

Trump, a climate-change dismisser and denier, answers evidence of impending disaster with a declaration that “I don’t believe it.”

He discourages Americans from worrying at precisely the point when, as David Wallace-Wells explains, “the wisdom of catastrophic thinking” is beyond serious debate.

Trump’s deeds—such as pulling the United States out of the global coalition that had been developed to curb the emissions that contribute to the crisis, encouraging expanded fossil-fuel production, and appointing burn-the-planet fanatics to key posts—mark him a bad actor. But history may well see his justification of inaction as the strongest argument for placing him at the very bottom of the list of worst presidents.

No one should forget that when a cold wave hit in January 2019, Trump responded by mocking climate change, with a tweet that concluded: “Wouldn’t be bad to have a little of that good old-fashioned Global Warming right now!”

When a president tells Americans, and others around the world, that it is appropriate to neglect, avoid, and deny the glaring evidence of a crisis, he guarantees that the crisis will become more daunting, more intractable, more deadly.

Even if the United States eventually panics, even if Trump eventually panics (and rule nothing out with this man), the president’s “don’t panic” counsel at a point when a sense of urgency was required is very likely to be his most dramatic and damaging legacy. And history will damn him for it.