Donald Trump has already staked his claim to the worst idea in immigration policy—a retrograde mass deportation scheme that was once known as Operation Wetback—but there are plenty of other cockamamie schemes to solve the problem of having a country that workers want to move to. On Wednesday, self-professed teen stabber Dr. Ben Carson announced his own at a press conference.

“Very easy question,” said Carson, before launching into an explanation of how the best way to secure our borders against “illegal immigration” is to build a literal fence like the one in Yuma, Arizona. Militant, yes, but certainly not outside the GOP mainstream.

But here’s where he rides this crazy train right off the rails: “The other thing you have to do, is you have to decrease the incentives for people to come here. So you have to get rid of all of the things that they would be getting if they can get through the system.”

And how would President Carson make moving to the U.S. undesirable? He eventually winds back around to explain: Much like American businesses have done in Cameroon, he’d like U.S. companies to go into Mexico and set up large farms that employ local workers while reaping a substantial profit. (In Cameroon, that profit mainly comes through land grabs, but who’s counting?)

If they can farm in Mexico, he figures, why would people bother coming to the U.S.?

“Make America Great Again” was already taken. Might as well move in on that wide-open “Make Mexico Great Again” territory, right?

Except, as Tom Philpott at Mother Jones points out, Carson’s plan won’t help Mexico. In fact, it’s that very policy that drove Mexican agricultural workers to seek jobs in the U.S. to begin with.

When the U.S.-led “Green Revolution” industrialized Mexican farms in the 1940s and 1950s, millions of workers (especially on small farms) were pushed out of work, driving them to the U.S. to find work.

But that’s no longer a problem. Carson admits the American farm owners he’s spoken to rely on immigrant workers to stay in business, and statistics suggest net migration from Mexico to the U.S. has been near zero since 2010. Continuing to hype up an alleged flood of illegal immigrants is just a xenophobic scare tactic at this point.

Each time the U.S. has dicked with the Mexican agricultural economy, as Carson’s bizarre plan proposes to do, it’s only managed to hurt the Mexican farm business in a way that drives increased immigration to the U.S. (See, e.g., NAFTA.)

If you think more Mexican workers entering the U.S. is a bad thing—as the GOP has to, because what happens if those people eventually become citizens and then vote?—Carson’s plan doesn’t make any damn sense.

But “it’s not difficult,” he says.

[h/t Mother Jones]