Trump promises mass deportations of undocumented people. How would that work? • New Hampshire Bulletin

Trump has repeatedly vowed in campaign rallies that he plans to go back to tough immigration policies of his first term in office.

Historians, lawyers and immigration and economic experts say removal of the more than 11 million undocumented people in the country would require enormous amounts of resources and overcoming legal hurdles.

The effects on the U.S. economic and social fabric would be profound, they said.

The Eisenhower administration claimed it deported 1 million people back to Mexico , but the real number is a couple hundred thousand .

The Eisenhower program was not as successful as thought, an immigration expert says.

The most recent mass deportation campaign came during the Obama administration.

The early architects of the Trump administration have laid out a second term that would expand the use of executive authority.

The Alien and Sedition Act , an 18th-century wartime law, allows the executive branch to deport any noncitizen from a country that the U.S. is at war with.

It can also be used for extraordinary measures that are not deportation, including the last time it was invoked after the bombing of Pearl Harbor led to internment camps of more than 120,000 people of Japanese descent.

State and local cooperation in detaining immigrants could be a challenge.