President-elect Donald Trump promises a hard line on illegal immigration and has spoken approvingly of the deportation efforts during the administration of the American president claimed by Kansas — Dwight Eisenhower.

The New York businessman turned president-to-be has praised how the 1950s Republican president’s administration sought to enforce immigration law by apprehending and deporting hundreds of thousands of undocumented Mexican immigrants, with some American citizens also caught up in the dragnet.

Trump’s most prominent references to the Eisenhower administration came nearly a year ago. But as a newly-elected president, his brash policy prescriptions carry added weight and are drawing fresh attention.

Called "Operation Wetback" and carried out in cooperation with the Mexican government, the deportation effort began in 1954. Trump has made clear he sees the operation in a positive light.

"Let me just tell you that Dwight Eisenhower, good president, great president, people liked him. ‘I like Ike,’ right? The expression. ‘I like Ike.’ Moved a 1.5 million illegal immigrants out of this country, moved them just beyond the border. They came back," Trump said during a November 2015 Republican debate.

"Moved them again beyond the border, they came back. Didn’t like it. Moved them way south. They never came back," Trump said. "Dwight Eisenhower. You don’t get nicer. You don’t get friendlier. They moved a 1.5 million out. We have no choice. We have no choice."

Politifact has said historians believe the 1.5 million figure likely is too high.

Trump centered his campaign in large measure on a promise to build a wall along the U.S.-Mexico border and make Mexico pay for it. He also said in a major immigration address in August the only path to legalization for the approximately 11 million undocumented immigrants is for them to leave the country and return legally.

Trump didn’t make clear in that speech whether he would seek to compel undocumented immigrants to leave. Yet earlier statements suggest he will dedicate forces toward deportation.

"We’re rounding them up in a very humane way, in a very nice way," Trump told 60 Minutes in 2015. "And they’re going to be happy because they want to be legalized."

Opponents of mass deportations argue such an undertaking would prove massive, costly and complex — let alone the moral and humanitarian implications of displacement.

"As a businessperson, Trump should readily understand that mass removals — particularly of the millions who are daily contributing their knowledge and hard work to our economy and to raising United States citizen children — are bad economic and security policy," Thomas A. Saenz, the president of Mexican American Legal Defense and Educational Fund, said in a statement.

The pro-immigration group America’s Voice has estimated deportations on the scale imagined by Trump would amount to 211 Greyhound buses running around the clock to Mexico each day and numerous planes flying at all times to take individuals back to countries not bordering the U.S.

Kansas Secretary of State Kris Kobach predicted in the beginning months of Trump’s candidacy that the businessman’s hard stance on immigration policy wouldn’t harm him politically.

Kobach has been a vehement supporter of Trump’s immigration policy, and has said he advised Trump on immigration. On Wednesday, he told reporters he will help advise Trump’s transition efforts.

In August 2015, just two months after Trump began his presidential campaign, Kobach dismissed recommendations that the GOP should embrace immigration reform in the wake of Mitt Romney’s 2012 defeat.

On election night, Trump emerged victorious.

"There were groups on the left that wanted to scare Republicans into thinking that being for enforcing the law is politically bad for you and bad for a president," Kobach said in 2015, "but that was a politically driven agenda that they had, and not true."