Washington — It is grotesquely fascinating to see Donald Trump’s apologists try to explain his most lunatic ideas and claims. It is a bit like watching someone choke down a sheep’s eye on a bet, then declare it fine dining. (Note to animal rights activists: This is a simile, not a recommendation.)

This process has a number of steps — the stages of servility. At first, there is stunned silence. (Did he really propose to buy Greenland?) Then the frantic search for hidden wisdom. (Climate change — which the president sometimes views as fake science — will melt Arctic ice, open sea lanes, and turn Greenland into the Panama Canal of the north.) Then the determined Googling of historical precedents. (Harry Truman, it turns out, also contemplated a Greenland grab.) Then growing defiance. (Greenland has loads of zinc! Doesn’t America deserve zinc?!)

Trump’s idea of disrupting hurricanes with nuclear weapons — a suggestion he has denied making, but almost certainly made — has duplicated some of these stages. According to Axios, one briefer who received Trump’s proposal was “knocked back on his heels.” “You could hear a gnat fart in that meeting,” a source recalled. An administration source tried to defuse the matter by pointing to Trump’s good intentions: “His goal — to keep a catastrophic hurricane from hitting the mainland — is not bad. His objective is not bad.” Which would be cold comfort to those with nuclear fallout in their backyard. The “bomb the hurricane” idea, it turns out, was also advocated in the decades following World War II. (During the early to mid-20th century, radioactive material had a somewhat milder reputation, being sometimes added to toothpaste, cosmetics, cigarettes, condoms and suppositories.)

Are such ideas as the Greenland purchase and nuclear weather control dangerous? Not because they are likely to be implemented. Denmark’s Prime Minister stands in stout resistance to the first proposal. And between Trump’s suggestion in a security briefing and the nuking of Hurricane Mindy are numerous steps, including (one would hope) the invocation of the 25th Amendment.

But we should not downplay the importance of having a president with harebrained notions. We should not explain away the craziness.

Certainly the president should not be allowed to lie away the craziness. In the face of good reporting on Trump’s nuclear idea, his claim of “FAKE NEWS” is entirely unconvincing. We have reached the point where the president’s denial of a charge actually makes it more credible. Recall his claim that the “Access Hollywood” tape isn’t real. And the claim that he never said Mexico would pay for the wall. And his claim that he never ordered White House counsel Don McGahn to fire special counsel Robert Mueller. And his claim that he never said Russia didn’t meddle in the 2016 election. And his claim that he never paid for the silence of a porn star. Self-serving deception by the president is now a justified expectation.

Loopiness at the highest level encourages a certain type of staff response. According to the Axios report on the nuclear proposal, the shocked national security briefer answered, “Sir, we’ll look into that.” Which is the answer of a staffer hoping the topic will never be raised again. Under a president like Trump, a considerable amount of White House staff time and energy is devoted — not to managing urgent crises or pursuing the country’s good — but to minimizing the damage of the boss’s strangeness and poor judgment. In this type of atmosphere, the agenda is often set by a leader’s obsessions, rather than by opportunities or obligations. Staffers must hold their breath at every presidential press availability, and during every tweet storm, wondering what random, ridiculous notion might dominate their week, or month, or year.

Former Sen. Bob Corker, R-Tenn., once referred to Trump’s White House as an “adult day care center.” This means, among other things, that it can’t properly focus on the needs of the nation.

Outside of government, it is easy for Trump’s followers to become invested in his nonsense. The authority of the presidency can give absurd proposals and theories a veneer of credibility. And because of the demands of political tribalism, lunacy can become defined as loyalty. Craziness can spread like a flu epidemic. However low Trump goes, his supporters go low with him.

And then there is the risk — however effective the White House staff, the legislature, and the courts may be at blocking Trump’s pixilated ideas — that one of them might slip through. And let’s hope it has nothing to do with nuclear weapons.

— Michael Gerson is a columnist for Washington Post Writers Group.