How could the U.S. military be used for Trump's mass deportation plan?

President-elect Donald Trump has pledged to use the U.S. military to carry out mass deportations.

Immigration and Customs Enforcement's deportation branch has only 6,000 agents and 41,000 detention beds.

The Department of Defense has provided operational support to immigration and border authorities for decades .

The Posse Comitatus Act bars federal armed forces from participating in law enforcement activities unless expressly authorized by Congress .

The 1807 Insurrection Act allows the president to utilize the military in domestic cases that warrant it.

The most recent time it was used was in 1992 by President George H.W. Bush after city and state leaders asked for federal help to quell the L.A. riots.

"It's going to be astronomically expensive," Nunn said. "And not only is it going to be straightforwardly expensive, but it's also going to come with opportunity costs every military service member and military asset that is diverted to assist with a mass deportation program or to assist with border security is a service member or asset that is not carrying out their normal duties.".