Former White House staff secretary Rob Porter (left), White House chief of staff John Kelly and White House senior adviser Jared Kushner cross the White House South Lawn in August. Kelly on Friday outlined new security clearance protocols after questions were raised about Porter's access. Alex Brandon/AP hide caption
White House press secretary Sarah Huckabee Sanders with then-staff secretary Rob Porter in August. In the wake of Porter's resignation, Sanders has reassured reporters that President Trump is sympathetic to victims of domestic abuse. Alex Brandon/AP hide caption
White House chief of staff John Kelly and staff secretary Rob Porter leave the White House on Friday. Porter resigned Wednesday following domestic abuse allegations. Manuel Balce Ceneta/AP hide caption
Senate Minority Leader Chuck Schumer of New York speaks to reporters following a policy luncheon Tuesday on Capitol Hill in Washington, D.C. Andrew Harnik/AP hide caption
White House chief of staff John Kelly pauses to look to a video monitor as he appears on Special Report with Bret Baier on Fox News in Washington, on Wednesday. Carolyn Kaster/AP hide caption
White House Chief of Staff John Kelly listens as President Trump speaks at the White House on Oct. 19. Kevin Dietsch/Pool/Getty Images hide caption
President Trump's cooperation with congressional Democratic leaders Nancy Pelosi (left) and Chuck Schumer (center) appears to have won public approval. Nicholas Kamm/AFP/Getty Images hide caption
President Trump speaks with newly sworn-in White House chief of staff John Kelly at the White House on July 31. Kelly is one of four former generals who were appointed to top administration positions. Jim Watson/AFP/Getty Images hide caption
Anthony Scaramucci blows a kiss to the gathered press in the White House briefing room on July 21, as White House press secretary Sarah Huckabee Sanders stands by. Chip Somodevilla/Getty Images hide caption
New White House chief of staff John Kelly was sworn in by President Trump on Monday. Evan Vucci/AP hide caption
In a tweet Friday evening, President Trump named John Kelly, secretary of homeland security, as his new chief of staff. Drew Angerer/Getty Images hide caption
Secretary of Homeland Security John Kelly (left) and Chief of United States Border Patrol Ronald Vitiello during a meeting held at the San Ysidro Port of Entry in San Diego in February. Denis Poroy/AP hide caption
Secretary of State Rex Tillerson (from left), Mexican Foreign Minister Luis Videgaray and Mexican Interior Minister Miguel Angel Osorio Chong greet each other during a news conference in Mexico City on Thursday. Ronaldo Schemidt/AFP/Getty Images hide caption
A photo released Tuesday by U.S. Immigration and Customs Enforcement shows people being arrested during an ICE operation. Charles Reed/U.S. Immigration and Customs Enforcement/AP hide caption
Homeland Security Secretary John Kelly says potential terrorists may have already entered the country. We won't know "until the boom," he said before a congressional panel. Andrew Harnik/AP hide caption