Jonathan Chait has an op-ed in the Times today about how the true Republican religion isn’t Christianity; it’s tax cuts. Republicans are allowed to dissent on social and cultural issues, but they’re never, ever, ever allowed to dissent on tax cuts. Coincidentally, just last night I finished reading Chait’s new book, The Big Con: The True Story of How Washington Got Hoodwinked and Hijacked by Crackpot Economics, in which he fleshes these ideas out. The first part of the book is about how the tax-cut loonies took control of the Republican Party; the second is about how the Republicans took control of the national debate.

As this chart shows, under Eisenhower, the top tax rate was 91 percent – can you even imagine that? – and the economy thrived. Throughout most of the 1980s, the top tax rate was 50 percent, and the economy boomed. It then went down to 28 percent, then up to 31 percent. Then Clinton raised the top tax rate to 39.6 percent – and the economy began thriving again. (More historical tax information here.)

Chait makes the point that tax cuts are not the only factor in economic growth; there are many factors. There’s a business cycle, growth and recession, but Republicans don’t believe in the business cycle; they believe everything is controlled by tax levels. The tax-cut theocrats predicted that Clinton’s tax increase would wreck the economy. When the economy actually boomed instead, they changed their explanation and said that it was really the aftereffects of Reagan’s economy that were causing the boom. As Chait points out, if you have to change your explanation after the fact, it’s not science. Anyone can come up with a cause-and-effect analysis after the fact. The true test is if you can accurately predict the results. The tax-cutters’ predictions failed. Supply-side economics is a joke.

As for Reagan, whom economic conservatives have deified, he was never as unbending as they say he was. He agreed to tax hikes in 1982 and 1983; in 1986, he lowered the top tax rate but raised the proportion of taxes paid by the rich. And “deified” is accurate, because tax-cutting really is a religion. Conservatives love certainty. Chait (pp. 235-36):

Most of us tend to think of liberalism and conservatism as clashing ideologies, with the former preferring more government and the latter preferring less. What separates the two sides, though, is not just goals but epistemologies. Conservatives do not simply believe that government ought to be limited vecause it is the best way to achieve certain goals. They believe it as a matter of philosophical first principles…

Liberal support for bigger government, on the other hand, is entirely rooted in what liberals believe to be its practical effects… Increasing the size of government does not, in and of itself, serve any greater purpose….

Conservatism thus has a certainty about it that rarely can be found in liberalism. In this way, the ideological style of conservative discourse resembles that of communism much more than liberalism. It has an air of totalistic ideology. It’s no surprise that a disproportionate number of conservative intellectuals were once communists… They simply exchanged the primacy of the state for the primacy of the market.

There’s more to the story — I’m simplifying Chait’s argument a bit. And no writer’s arguments should ever be swallowed uncritically. Nevertheless, the book is intriguing and well worth reading.