From Politico:

Homeland Security Secretary Jeh Johnson has withdrawn from consideration in the fits-and-starts search for a new defense secretary, according to a report Monday, making him the latest leading candidate to pass on the opportunity to run the Pentagon under President Barack Obama. Johnson has told the White House that he prefers to stay at DHS, The Associated Press reported, citing “people familiar with the process.” He was considered a leading contender to replace Chuck Hagel, whom the White House pushed out last week.