“Practical men who believe themselves to be quite exempt from any intellectual influence, are usually the slaves of some defunct economist,” wrote John Maynard Keynes. Today we’re witnessing a populist backlash against political establishments, especially in the Republican Party, and the defunct economist who best explains it is Mancur Olson (1932-1998).

In The Rise and Decline of Nations, Olson described how a successful economy would descend into stagflation and immobility through a paralyzing growth of regulations and barriers to business entry. Interest groups will become more and more powerful until they strangle the economy with wasteful laws and red tape that transfer wealth to themselves at the expense of the economy as a whole. When that happens, Olson suggested, the best we can hope for is a revolution that pulverizes the special interests. The problem is that this ordinarily requires something like the kind of crushing military defeat Germany and Japan suffered after Word War II, and that’s not something anyone would wish on the United States.

On a smaller scale, however, parliamentary countries have shown themselves able to turn things around when voters have had enough and a majority government comes to power with a real reform agenda. With its sclerotic separation of powers, that’s harder to do in a presidential country such as the United States. Given gridlock and the lack of a legislative reverse gear, presidential countries must normally wait until their problems reach crisis levels before they can act.

And that explains the Trump revolution. His supporters understand that we’re in the kind of crisis described by Olson, one in which the country must continue to decline and in which our children will never have it as well off as we did, unless there’s a radical change. Sensing that, they’re willing to forgive the troubling things they hear Trump say, the personal invective, the attacks on a federal judge, the willingness to waterboard.

Don’t you get it, the NeverTrump people ask us? Yes we do. We’re not happy about it, and we’d like to think things like that would never happen. We like it when Trump reverses himself, as he often does.

But what about you, we ask them. Our country is in decline. Don’t you get it? Or are you simply too comfortable with the way things are? I once gave a talk to a group of conservatives about the rise of an American aristocracy, and a D.C. insider from the audience thought to correct me. Yes, he said, we’re going to Hell in a hand-basket, but this time we’ve got a lot of great little magazines and think tanks on our side. However bad it might be for the country, I’ve got mine!

These are the people who, conscious of their own salvation, gave us the distinction between themselves and the 47 percent of takers. I thank Thee, Lord, they pray, that I am not as they are, the unjust, the adulterers, the publicans with their Make America Great Again caps.

Their smug self-satisfaction reaches odious heights when they lecture us on the rottenness of Trump supporters. Here is National Review’s David French, on our moral failings. “Americans are killing themselves and destroying their families at an alarming rate. No one is making them do it. The economy isn’t putting a bottle in their hand. Immigrants aren’t making them cheat on their wives or snort OxyContin.”

In the circumstances, the unwashed Trump supporter can be forgiven for thinking that the scribes and hypocrites have given up on him. And if Trump chooses to shock them, so much the better. What the Trump supporter understands is another economic theory, called signaling: Promises are more credible when the promisor is willing to bear a cost in making them. Bankers are more willing to believe the guy who backs up his loan application by offering to mortgage his house, and we’re more likely to believe that Trump will clean out the stable if he shows that he’s willing to be politically incorrect. And the more we wince, the more we believe his promises.

Dangerous talk, says the NeverTrumper, who is quick to detect a whiff of fascism in the air. Trump would rule like a strongman, they tell us. I don’t know where people have been, but we’ve been ruled by a strongman for the last eight years, and it’s not as if things would be much different under Queen Hillary. As for fascism, that’s ridiculous. There’s a kind of person, remarked Hannah Arendt, who always feels as if the dark night of fascism is about to descend on the United States — but somehow it always lands in Europe. Americans don’t do fascism, and especially a guy from Queens doesn’t do fascism. If you’re looking for someone who’s intolerant, a jumped-up Robespierre, you’re more likely to find him in a college tearoom than in a construction site or in the Trump Tower. As for the NeverTrump crowd, they’ve shown they can give lessons in intolerance.