About a decade ago, I agreed to have an off-the-record lunch in San Diego with the sector chief of the Border Patrol. The meeting lasted three hours. At one point, I asked my lunch companion a simple question: What do you need?

You see, most politicians show up for photo ops at the border, like former President Donald Trump and current President Joe Biden did recently in Texas, and then they pontificate about what they’re prepared to give the Border Patrol. Its politicians lecturing the cops about what should be done. And it’s a total farce.

As a son of a retired cop who was on the job for 37 years, and the grandson of a Mexican immigrant who came legally before 1920 and left the country better than he found it, I can appreciate just how complicated the immigration debate really is. So I want to know from an expert on border security, what the chief needed to make the U.S.-Mexico border more secure and make it easier for his agents to do their jobs. As a journalist, I was prepared to do something that politicians won’t ever do: Shut up and listen.

The chief didn’t want a 2,000-mile “big beautiful wall” or more Border Patrol agents. Basically every bad or half-baked idea you can think of that some politician has dreamt up, this border cop wanted no part of it, nothing to do with. Instead, the chief explained, what he could really use was just three things—tunnel detection equipment, high-tech surveillance gadgets, and better roads to allow Border Patrol vehicles to access what is often rugged terrain on the border. Everything the chief wanted would likely have been more effective than the political soundbites and applause lines we have now.

That conversation and what it taught me comes to mind now as I see what Trump is planning to do to solve the immigration crisis, and that is create a whole new crisis.

Trump is promising mass deportations. If he’s reelected, he wants to forcibly remove as many as 10 million people. He says he plans to pull this off by creating a force magnifier. He wants to deputize local and state police and federalize State National Guard units, and then unleash them to hunt for suspected undocumented immigrants. In other words, anyone who these officials, none of whom have training in immigration enforcement, think maybe in the country illegally, could be rounded up and deported. This is a cut and dried recipe for ethnic profiling. And the number one target for inconvenience and maybe even incarceration will be Latinos, including those in the southwest, whose family sometimes go back as far as the early 1800s. That’s right, it may go. We were here to welcome your people.

We’ve traveled this road before in U.S. history as Americans and always wind up at a dead end. In the 1930s, President Herbert Hoover needed a scapegoat for the Great Depression caused by the stock market crash of 1929. And he centered on a group of simple and hardworking people living out in the southwest. Don’t ask me why, those dots are hard to connect. Anyway, Hoover gave tacit approval to efforts by state and local governments to round up and expel scores of Mexicans and Mexican Americans and send them south of the border. In all, between 1930 and 1939, as many as 2 million people wound up leaving the United States from Mexico, some voluntarily after losing their jobs, and others forcibly removed after being put on railroad cars.

Between 1930 and 1933, federal government officers deported more than 80,000 people. By some estimates, more than half of those who were rounded up, deported and pressured to leave, more than half were U.S. citizens, Mexican Americans born in the United States.

That was a tragedy and an injustice as egregious as the wrongful incarceration of Japanese Americans in internment camps during World War Two. It just didn’t make it into all that many history books. Not to worry though, historians may get another chance. If Trump is reelected and keeps his evil promise, a sequel could be in the works.