President Donald Trump has tuned out his national security staff and soured on Defense Secretary James Mattis because he has come to doubt his political loyalties.
As Trump has grown more confident as commander in chief, he has started making more decisions without the input of Mattis and other experienced staffers, reported the New York Times.
His relationship with the defense secretary, whom he once hailed as "Mad Dog" -- a nickname the retired Marine Corps general hates -- has soured in recent months, according to more than a dozen White House, congressional and current and former Defense Department officials interviewed over the past six weeks.
Trump has gotten tired of Mattis being described as the adult in the room, and he's growing concerned the Cabinet official is a Democrat at heart, according to sources.
Mattis has balked at some Trump requests, such as slow-walking a ban on transgender troops and refusing to stop family members from accompanying troops deployed to South Korea.
Trump and Mattis have clashed in the last four months of NATO policy, large-scale military exercises in South Korea, and the president's decision to withdraw from the Iran nuclear deal.
The president wants Mattis to be more of a cheerleader, like Secretary of State Mike Pompeo, but friends and aides say the defense secretary is not comfortable getting involved in political advocacy.
“Secretary Mattis lives by a code that is part of his DNA,” said Jeff Davis, who recently retired from the U.S. Navy after serving as a spokesman for the defense secretary. “He is genetically incapable of lying, and genetically incapable of disloyalty.”
Mattis has declined multiple requests by the White House to appear on "Fox & Friends" to praise Trump's agenda, and he hasn't done many public, on-the-record interviews.
The arrival earlier this year of Mira Ricardel, a former Boeing executive and Trump campaign aide with a history of bad blood with Mattis, has increased speculation that the defense secretary would be out after the midterm elections -- which could hurt the president's relationship with GOP moderates.
“Secretary Mattis is probably one of the most qualified individuals to hold that job,” Sen. Jack Reed (D-RI), the ranking Democrat on the Senate Armed Services Committee. "(His departure) would, first of all, create a disruption in an area where there has been competence and continuity.”