Trump's mass deportation plan—a bad idea recycled from the 1930s

If Donald Trump's mass deportation plan seems eerily familiar, that's because it is. We tried this in the 1930s and apparently with no regard for what was legal at the time.

During the Great Depression, counties and cities in the American Southwest and Midwest forced Mexican immigrants and their families to leave the U.S. over concerns they were taking jobs away from whites despite their legal right to stay.

The result: Around 500,000 to 1 million Mexican immigrants and Mexican Americans were pushed out of the country during the 1930s repatriation, as the removal is sometimes called.

During that time, immigrants were rounded up and sent to Mexico, sometimes in public places and often without formal proceedings. Others, scared under the threat of violence, left voluntarily.

About 60 percent of those who left were American citizens, according to various studies on the 1930s repatriation. Later testimonies show families lost most of their possessions and some family members died trying to return. Neighborhoods in cities such as Houston, San Antonio and Los Angeles became empty.

That's the history Trump wants to repeat—indiscriminately kicking out undocumented immigrants and U.S. citizens alike and significantly squeezing the populations of many American cities. God only knows what the process of actually deporting 11 million-plus immigrants would look like. Not to mention the cost.

The conservative-leaning American Action Forum concluded in a report it would cost between $400 billion to $600 billion and take 20 years to remove an estimated 11.2 million immigrants living in the country illegally.