Homeland Security Secretary Kirstjen Nielsen is officially out of a job as of Sunday afternoon, after a tumultuous 16-month tenure that made her a public face of the Trump administration’s immigration crackdown. Nielsen’s resignation came just days after President Donald Trump withdrew the nomination of Ronald Vitiello to lead the Immigration and Customs Enforcement agency—a move that Nielsen was reportedly blindsided by. Trump confirmed the news in a tweet Sunday evening, revealing that the current head of Customs and Border Protection, Kevin McAleenan, will now serve as acting DHS secretary: ….I am pleased to announce that Kevin McAleenan, the current U.S.