Here's who could replace Kirstjen Nielsen at Homeland Security

Amid a national emergency on the southern U.S. border, President Trump made two big changes at the Department of Homeland Security.

On Friday, the White House pulled the nomination of Ron Vitiello to be the permanent director of U.S. Immigration and Customs Enforcement after he served as the acting director of the agency since June 2018. A couple of days later, Trump fired DHS Secretary Kirstjen Nielsen, a move that took many by surprise but was widely welcomed by immigration hardliners.