Last week, to the shock and horror of virtually everyone, Donald Trump announced that “trade wars are good” and that he would be starting one by slapping tariffs of 25 percent and 10 percent on steel and aluminum imports. The declaration was distressing for a number of reasons, including 1) that it was only supported by Trump’s craziest advisers; 2) that it will hurt American companies and consumers; and 3) that countries around the globe, including key allies, have already warned they’ll have no choice but to retaliate if their products are included in the tax, which Commerce Secretary Wilbur Ross suggested on Friday is a virtual certainty. Even more disturbing? The president seems to have little to no grasp on the actual economics involved.

Trump’s opinion on the benefits of tariffs hasn’t changed much since the 1980s, the decade in which his brain apparently ossified. (Then, Trump was obsessed with the Japanese instead of the Chinese, but the principle, for him, is effectively the same.) Still, the president has occasionally entertained the notion that there will be a debate over the trade war he has been demanding since the earliest days of his campaign. Axios paints the picture with an account of a meeting in the Oval Office last January, in which Trump had his anti-tariff advisers (National Economic Council head Gary Cohn and recently departed staff secretary Robert Porter) debate his pro-tariff advisers (Ross and Peter “NAFTA leads to infertility” Navarro) for his pleasure. Trump, in full Apprentice mode, watched the back-and-forth like a tennis rally, offering useless commentary and ultimately declaring himself to be an “economic nationalist” and therefore in favor of the punitive measures, seemingly without any idea what that meant:

Cohn tried to argue that these tariffs would ruin Trump’s record-setting stock market streak and wipe away benefits of tax reform . . . Navarro argued that Trump needed to protect the domestic industry, promote American jobs, and show the world we were going to be tough on trade, and this was the best way to do it. Porter argued tariffs would hurt the manufacturing industries that use steel and aluminum as inputs, tax American consumers, roil global markets, alienate allies, and lead to retaliation.

Trump sat and watched the fight. He occasionally interjected, saying things like, “I need to take care of my base,“ “You can’t have a country without steel,” and “Peter, what do you say to that argument?” By the end, Trump told Porter he didn’t realize he was such a “globalist.”

So, basically, Trump decided to start a trade war because his base thinks “globalist” is the most insulting thing you can call a person, economic effects be damned. And now, the G.O.P. is worried that Trump’s ignorance will cost them the midterms, something they probably should have thought of when he announced his candidacy for president:

Republicans plan to brag about the economy in midterm campaigns in hopes of countering Trump’s unpopularity, touting a strong stock market, low unemployment rate, and—most importantly—their increasingly popular tax legislation. But Trump’s suggestion Saturday that he might slap penalties on European cars, in addition to the tariffs on aluminum and steel he already promised, could upend that strategy completely, Republicans say.

“Should the administration opt to move forward with tariffs on steel and aluminum, American manufacturers, businesses, and consumers would be forced to bear the brunt, paying more for steel and steel products,” Senate Finance Chairman Orrin Hatch told Politico. “Such action could very well undercut the benefits of the pro-growth tax reform we fought to get on the books.” Which could be a real problem for Republicans, if trade wars weren’t so “easy to win!”