Chad F. Wolf, the acting secretary for the Homeland Security Department, resigned on Monday, just nine days before he was expected to help coordinate the security of a presidential inauguration facing heightened threats of violence.
Mr. Wolf told employees of the Homeland Security Department he would be stepping down on Monday night in part because of court rulings that invalidated some of the Trump administration’s immigration policies, citing the likelihood that Mr. Wolf was unlawfully appointed to lead the agency.
“Unfortunately, this action is warranted by recent events, including the ongoing and meritless court rulings regarding the validity of my authority as Acting Secretary,” Mr. Wolf said in the letter obtained by The New York Times. “These events and concerns increasingly serve to divert attention and resources away from the important work of the Department in this critical time of a transition of power.”
Mr. Wolf did not address the deadly siege of the Capitol in his letter. Peter T. Gaynor, the administrator of the Federal Emergency Management Agency, will replace Mr. Wolf as the acting secretary of the Homeland Security Department. He will now be tasked with helping ensure the security of the inauguration of President-elect Joseph R. Biden Jr. The Secret Service, which falls under the Homeland Security Department, is leading the security efforts for the event.
Mr. Wolf will remain with the department as an under secretary for policy, a position for which he was confirmed by the Senate, according to Chase Jennings, a homeland security spokesman.
President Trump has overseen a Homeland Security Department that has been riddled with vacancies, creating a revolving door of temporary leaders who faced repeated questions over the legality of their positions. A federal judge in September ruled that Mr. Wolf’s predecessor, Kevin K. McAleenan, likely violated the proper order of succession and he lacked the authority to install Mr. Wolf as acting secretary.
A federal judge in New York agreed in November that Mr. Wolf had not been legally appointed and as a result invalidated his suspension on protections for immigrants known as “Dreamers” brought to the United States as children.
Mr. Wolf emerged as one of Mr. Trump’s more loyal cabinet officials during his time leading the department, becoming the public face of the department’s deployment of federal agents to respond to unwieldy protests in Portland, Ore., around a federal courthouse. Last week, he issued a statement calling on Mr. Trump to condemn the riots at the Capitol.