WASHINGTON — Welcome to what I’ve called “the politics of self-esteem.” By this, I mean that increasing numbers of people, on both the right and left and most with good intentions, have become politically engaged because it makes them feel better. It raises their self-esteem. This phenomenon predates Donald Trump’s candidacy, but it helps explain a Trump puzzle that baffles many observers.

By now, the puzzle is familiar. Trump repeatedly says things that seem (by conventional wisdom) hateful, offensive, stupid or simply wrong. But instead of these apparent missteps backfiring, just the opposite happens. The more Trump flouts prevailing norms, the more popular he becomes among Republicans. The latest example: After proposing a widely criticized ban on all Muslims entering the country, his support among Republicans jumped to 38 percent in December from 32 percent in November, according to a Washington Post-ABC News survey.

Trump has not redefined politics, but he has exploited a fundamental change of recent decades. Since World War II, much of national politics has involved a struggle for economic benefits. In 1940, the government transferred about 7 percent of national income from some groups to others. Now, that share is nearly 20 percent. This remains a huge part of politics, as debates over highway spending, farm subsidies, taxes and so much more remind us. But spending decisions are incremental; sweeping shifts are unlikely. We’re not going to abolish Social Security.

Against this backdrop, politics is increasingly shaped by issues that are cast in moral terms: abortion, affirmative action, gay rights, global warming, guns, immigration and health care — to name a few. Compared with most economic matters, these issues are much more combustible politically. On many economic questions, you can negotiate compromises that please, or displease, almost everyone equally. There’s room for give-and-take. By contrast, compromises on moral questions are usually hard and often impossible.

Liberals pledge to save the planet; conservatives vow to end illegal immigration. But their very passion suggests that they feel morally superior to their opponents and crave anything that strengthens their sense of superiority. They receive what I call “psychic benefits.” Significantly, these psychic benefits do not require the enactment of legislative agendas.

What his supporters most like about Trump, even if they disagree with some of his policies, is that he defines himself — he does not let others do it for him, and this rubs off on them. It’s liberating. As he asserts his moral superiority over the judgments of the “political establishment” and “mainstream media,” so can his supporters defy others’ hostile judgments of their values. In the contest for the high moral ground, they have a champion and a spokesman.

For the “political establishment” and “mainstream media” — admittedly ambiguous groupings — this poses a dilemma. When Trump makes proposals that strike them as simplistic, unworkable, undesirable or, worse, racist, they have two choices, both bad. If they decide not to react, their silence may seem to condone policies that they abhor. The second choice is to denounce many of Trump’s ideas, but this plays into his hands because the more he is attacked by despised outsiders, the more popular and admired he becomes among supporters.

What results is a bizarre, though fascinating, spectacle. Trump proposes. His opponents (pundits, politicians, “experts”) pounce — criticizing and fulminating. And Trump’s popularity rises.

It is not inevitable that this cycle continue indefinitely. Trump may stumble. Some other candidate — or candidates — may soar. The avalanche of criticism may reach a critical mass, raising fresh doubts among some followers. Or Trump’s outsized ego may begin to offend onetime allies. Politics is a fickle business. Still, his success has so far stunned many veteran reporters and election observers who have underestimated his political skills.

The more durable lesson here concerns the politics of self-esteem. Our system of governance is increasingly infused with a sanctimony all along the ideological spectrum that makes political accommodation and compromise harder to achieve. Well-intentioned people often act in rigid ways that maximize their personal self-esteem while perversely making it harder for the country to govern itself.

Robert Samuelson is a columnist for The Washington Post.