Donald Trump said that if he were to become president of the United States, part of his immigration policy would be modeled directly after a 1950s policy called "Operation Wetback."

In an interview published online for 60 Minutes Overtime, Trump told CBS anchor and correspondent Scott Pelley that his immigration plan to deport all undocumented immigrants in the country and allow them to come in on a per-case basis can work because President Dwight D. Eisenhower did it more than half a century ago.

"We are rounding them up in a very humane way, in a very nice way, and they're going to be happy because they want to be legalized," Trump explained in the portion of his 60 Minutes interview that did not make air.

Trump went on to defend his policy by citing Eisenhower's 1954 immigration policy, Operation Wetback, which deported roughly 1 million undocumented immigrants to Mexico.

The policy, named after an offensive slur toward Hispanics, expelled Mexican nationals and U.S. citizens and transported them deep into Mexico so as to limit their chance of ever attempting to make it back into the United States, according to Huffington Post Latino Voices.

"It is practical, it's going to work," Trump told Pelley. "You look back in the 1950s, you look back at the Eisenhower administration; take a look at what they did and it worked."

But as both the Huffington Post and later the Washington Post have pointed out, many historians have blasted the policy as derogatory and inhumane. In fact, many believe the numbers and success of the Eisenhower program are overstated.

This is how the Washington Post described the program:

During the summer of 1955, this is where hundreds of thousands of Mexicans were “dumped” after being discovered as migrants who crossed the U.S.- Mexico border illegally. Unloaded from buses and trucks carrying several times their capacity, the deportees stumbled into the Mexicali streets with few possessions and noway of getting home.

This was strategic: the more obscure the destination within the Mexican interior, the less opportunities they would have to return to America. But the tactic also proved to be dangerous, as the migrants were left without resources to survive.

Operation Wetback was instituted by the federal government to kick out Mexicans who had been brought into the United States during the Bracero program, which purposely brought Mexican workers into the U.S. to do jobs others wouldn't do at the beginning of World War II.

Despite being pushed by Pelley in the interview about the impracticality of his idea, Trump stuck to his guns.

"I think it's going to work out very well," Trump said. "How does it work? It's called management."