I never thought I’d say this, but I miss voodoo economics.

It was shocking at the time when a crank economic doctrine — the claim that tax cuts pay for themselves — became in effect the official Republican Party line. It was dismaying to see that doctrine’s hold on the party become ever more entrenched even as the evidence for its falsity — the Clinton economic boom, the lackluster performance of the Bush economy even before the 2008 financial crisis, the tax-cut debacle in Kansas, the failure of the Trump tax cuts to generate an investment boom — kept accumulating.

And voodoo economics continues to do real damage to this day. The Republicans who control Mississippi, a poor state with desperately underfunded educational programs that’s closing hospitals, recently moved to boost the state’s economy by … cutting taxes.

As far as I know, however, diatribes about the evils of high marginal tax rates haven’t inspired any acts of domestic terrorism.

As has been widely reported, the suspect accused of fatally shooting 10 people in Buffalo is a devotee of “replacement theory,” which claims that sinister elites — especially Jews, of course — are deliberately bringing in immigrants to displace and disempower white Americans. So were the men charged with massacres at a Pittsburgh synagogue in 2018 and an El Paso Walmart in 2019.

Replacement theory used to be a fringe doctrine, but these days, in at best a thinly disguised form, it is attracting significant mainstream support within the GOP. And this mainstream acceptance helps it spread.

As The New York Times has documented, Tucker Carlson’s Fox News show has amplified the doctrine more than 400 times. And lest you dismiss Carlson as a mere media figure, remember David Frum’s dictum: “Republicans originally thought Fox worked for us. Then we discovered that we work for Fox.”

In any case, a growing number of prominent GOP politicians also espouse barely veiled versions of replacement theory. Elise Stefanik, the third-ranking Republican in the House, has run Facebook ads claiming that Democrats want to grant amnesty to immigrants in the country illegally to “overthrow our current electorate.” J.D. Vance, the Republican nominee for Senate in Ohio, claims that “Biden’s open border” is bringing “more Democrat voters pouring into this country.”

Why is the paranoid style taking over the Republican Party? Facts have little to do with it. Some of the most anti-immigrant politicians come from places with hardly any immigrants: Fewer than 5% of Ohioans and fewer than 4% of the residents of Stefanik’s district, in New York, are foreign-born. In New York City the share is almost 38%.

Nor does there seem to be a popular groundswell driving this political shift.

What has changed, however, is the behavior of Republican elites, who used to push back against conspiracy theories but now cheerfully embrace them whenever it seems politically expedient.

Which, I’d argue, is where voodoo economics comes in — not as an idea but as a determinant of the kind of people who became Republican politicians.

The rise of supply-side economics coincided with the rise of movement conservatism. Because the movement’s core ideology involved reducing taxes on the rich, it was lavishly supported by billionaires and corporate interests, and this in turn meant that it offered job security to anyone who remained sufficiently loyal.

So when I say that I miss voodoo economics, what I really mean is that I miss the illusion — which I shared — that the impact of its rise would mainly be limited to the politics of taxes and spending. What we now know is that the embrace of crank economics presaged the general moral collapse of the Republican establishment.

This collapse opened the door for paranoia and conspiracy theorists of all kinds — and the consequences have been deadly. There is, I would argue, a direct line from the Laffer curve, to Jan. 6, to Buffalo.

Paul Krugman is a New York Times columnist.