The president suggested 30,000 migrants could be housed on the base. It is unclear how the plan will take shape.

The Department of Defense said this week that it would provide planes for deportation flights.

Border enforcement agencies have spent billions assembling surveillance tools to track and find people. These could be critical in President Trump’s immigration agenda.

The shooting on Monday in Vermont near the Canadian border followed the surveillance of an armed couple who dressed in black tactical-style clothing.

The president-elect’s immigration advisers have warned Republicans that it will take time and money from Congress to carry out the mass deportation effort he has promised to execute immediately.

The size of the planned immigration raids is unclear, but they would be the opening step in the president-elect’s goal of overseeing the largest deportation program in history.

Thomas Homan once defended Obama-era policies and health care for transgender immigrants. Now he’s eyeing hotlines to report undocumented neighbors and arrests of local officials who get in the way.

New York’s status as a sanctuary city for undocumented immigrants has shifted over time. Now, as President-elect Donald J. Trump prepares to enter office, it may shift once again.

Most Democrats joined Republicans in voting to take up the measure, which would require the detention and deportation of undocumented immigrants charged with minor crimes.