President Trump said he's nominating Stephen Moore, a longtime supporter of the president, for a seat on the Federal Reserve Board. (Andrew Harrer/Bloomberg News)

Because I write and teach about the “dismal science,” people sometimes mistakenly refer to me as an economist, which usually means someone with a PhD in economics. I try to correct the misimpression with a bit of humor, explaining that “I just play one on TV.”

Now our reality-TV president is set to nominate Stephen Moore, a right-wing crackpot who has been playing a TV economist for decades, for a seat on the Federal Reserve Board.

I use the phrase “right-wing crackpot” after careful consideration of possible alternatives, recognizing that it’s generally not a good idea to criticize the motives or intelligence of those with whom you disagree. Unfortunately, “famous idiot” was already taken by New York magazine’s Jonathan Chait, who for two decades has been chronicling Moore’s unbroken string of false statements and failed predictions. I also might have gone with “charlatan and crank,” but New York Times columnist Paul Krugman, a real economist with a Nobel Prize, beat me to it.

During the 2008 financial crisis, Moore and I were in regular disagreement while appearing on a CNBC show hosted by another TV economist, Larry Kudlow, now President Trump’s top economic policy adviser. Back then, Moore was blaming the government rather than Wall Street for the market crash and warning that the heavy dose of fiscal and monetary stimulus then proposed by the Obama administration and the Fed would result in hyperinflation and a collapse of the dollar.

As it turned out, all that stimulus did just what real economists predicted, saving the country from a second Great Depression. A decade later, with the markets repaired and the economy running at capacity, an equally confident Moore is arguing just the opposite, calling for more stimulus rather than less.

The central features of Moore’s economic way of thinking? A stubborn refusal to learn from historical experience, embrace economic consensus or accept the world as it is rather than as he would like it to be. He led the charge in predicting that the Clinton and Obama tax increases would fail to raise additional revenue and drive the economy into recession. He turned out to be wrong on both counts.

The only way Moore is able to continue peddling his supply-side nonsense is to simply make stuff up, hoping nobody will notice. A few years back, Miriam Pepper, the editorial-page editor of the Kansas City Star, caught him lying red-handed in an op-ed she had published. She banned him from ever appearing on her pages again. Indeed, outside the alternate-reality bubbles of Fox News, the Heritage Foundation, the Wall Street Journal editorial page and the Trump White House, Moore has no credibility, even as a TV economist.

Moore’s nomination to be one of the seven governors of the Fed presents a sanity test for Senate Republicans and their enablers in the business lobby.

Any president, even this one, is entitled to surround himself with sycophantic advisers he considers personally and intellectually compatible (Moore’s latest book, “Trumponomics: Inside the America First Plan to Revive Our Economy,” was co-authored by Kudlow). And any president, even this one, is entitled to appoint a conservative, pro-business, pro-growth policy wonk to the Fed, including one without a PhD.

But no president is entitled to install an incompetent fool and ideological hack to the governing board of the world’s leading central bank, let alone for a term that could extend until 2030.

In nominating such an extravagantly unqualified person to such an important post, Trump is again trashing the political norms by which Washington has operated for as long as anyone can remember. In effect he is daring the Republican senators to defy him — and the angry mob he leads — if they choose instead to protect the professionalism and integrity of one of the country’s most respected and apolitical institutions. A vote to confirm Moore would be a craven capitulation to political bullying and partisan self-interest.

For years the business community has been trying to convince us that it is not merely a lobbying arm of the Republican Party willing to sell out the country for a tax cut and a bit of regulatory relief. Yet there is scant evidence that it has been willing to expend any political capital to resist the worst instincts of Trump and the tea party radicals.

Moore’s nomination offers the perfect opportunity for the business lobby to demonstrate its political independence and courage. Should they fail to take up the opportunity, however, business leaders will lose whatever credibility they have left as stewards of the American economy and champions of competent government.

Pearlstein is a Post business and economics columnist and Robinson Professor of Public Affairs at George Mason University. His book “Can American Capitalism Survive” was published last fall by St. Martin’s Press.