I had ridiculed Donald Trump’s call to deport all undocumented immigrants as well as their children born in the US who are, of course, US citizens. I felt that not only was it unfeasible in practice to round up and deport 11 million people, it was unthinkable and illegal in the case of the children. So I was shocked to learn on NPR today that such a mass deportation had in fact occurred in the past during the time of the Great Depression when the pressure for jobs resulted in Mexican-Americans and their US-born children being sent away.

During the 1930s and into the 1940s, up to 2 million Mexicans and Mexican-Americans were deported or expelled from cities and towns across the U.S. and shipped to Mexico. According to some estimates, more than half of these people were U.S. citizens, born in the United States.
…

It was the Great Depression, when up to a quarter of Americans were unemployed and many believed that Mexicans were taking scarce jobs. In response, federal, state and local officials launched so-called “repatriation” campaigns. They held raids in workplaces and in public places, rounded up Mexicans and Mexican-Americans alike, and deported them. The most famous of these was in downtown Los Angeles’ Placita Olvera in 1931.

Balderrama says these raids were intended to spread fear throughout Mexican barrios and pressure Mexicans and Mexican-Americans to leave on their own. In many cases, they succeeded.

It would be nice to think that this could not happen today but history teaches us that if you ratchet up fear and anger enough, then constitutional protections that we take for granted go out the window, the way they did with the internment of Japanese–Americans during World War II.