Washington — When it comes to Donald Trump, it is increasingly difficult to distinguish between a political strategy and a nervous breakdown. His tweeted trash talk, his meandering stream of consciousness press availabilities and his shameless embrace of sleaziness are not the signs of a healthy mind. Trump’s followers may eventually look up to find they were actors in someone else’s delusion.

But Trump’s recent self-defenses at least clarify his ambitions as an ethicist. Concerning the Ukraine scandal, the president is not seeking forgiveness for a failure in judgment, or even trying to change the subject. He boldly asks Americans to accept that his actions — pressuring a foreign power to investigate a domestic political rival — were good and proper. “I don’t care about [Joe] Biden’s campaign,” Trump insists, “but I do care about corruption.” And there was “tremendous corruption with Biden.”

Trump is effectively setting a new standard of political morality and requiring his supporters to defend it. He is asking elected Republicans in particular to agree with his claim that a practice uniformly viewed as corruption in the past is actually an example of fighting corruption. That is the little thing, the small thing, which Trump demands of his followers: To call hot, cold. To call black, white. To call wrong, right.

Philosopher Alasdair MacIntyre’s idea of “incommensurability” strikes me as relevant here. If all moral claims are merely “emotive” — statements about ourselves rather than the nature of reality — then there is no way to argue between them. The statement that “stealing is wrong” can be debated. The statement “I feel that stealing is wrong” is not subject to rational dispute. Someone else could simply assert, “I feel that stealing is right,” and the argument would be at a stalemate.

Trump is the emotivist par excellence. He holds no objective, abstract beliefs about the meaning of justice or duty. He approves of things that help him and disapproves of things that hurt him. There is no other moral grounding. Yet he makes his assertions with utter confidence.

The president currently claims that asking a dependent government to dig up dirt on a political rival is a good thing — even when it involves the implication of extortion. He makes no argument about why the traditional definition of corruption has changed. He feels no need. The shift is in his interest. And that is enough to require the assent of his followers.

Elected Republicans, as a result, are looking mighty uncomfortable. Mouthing the words that Trump wants from them — saying that corruption is really anti-corruption — would mean sounding like a fool and surrendering what remains of their political honor. Some, like Florida Sen. Marco Rubio, have lamely claimed that Trump was really making a joke. Because, you know, presidential corruption is normally such a laugh riot. But Trump has insisted on his own seriousness. Rubio and the rest must swallow the gelatinous pile of offal Trump gives them — all of it — or they are no longer in the club.

Republicans are being called to follow their leader down a relativist rabbit hole. Trump is not only asking them to accept his arguments on policy matters like building a wall or provoking a trade war. To be loyal foot soldiers, they must affirm that morality means what Trump says it means — even when it violates their clearest instincts. They know, deep down, that if a Democratic president had asked France or China for help in destroying a prominent Republican rival, they would be in a fever pitch of outrage. But, in the Trump era, this isn’t supposed to matter anymore. Consistency means nothing. Principle means nothing. Character means nothing. It only matters who wins.

Many Republicans would dearly like to say: What Trump did is wrong but it doesn’t rise to an impeachable offense. There are two problems with this approach. First, Trump will not regard this as evidence of sufficient loyalty. He demands full approval. And second, I imagine that most of the founders would regard Trump’s act — inviting a foreign country to influence an American election — as the definition of an impeachable offense. If their intent means anything, it means Trump is seriously corrupt.

So we are left with positions that can’t be reconciled. Trump honestly seems to have no moral objection to what he did. His opponents are left sputtering: But this has always been seen as serious corruption! The president simply doesn’t care. And, if his GOP supporters remain loyal, they will be further implicated in the moral decay of American politics.

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