Trump is reportedly thinking about getting rid of Mattis, and he's given 'Mad Dog' a new nickname

President Donald Trump is reportedly thinking about replacing James Mattis as defense secretary.
He has also reportedly replaced his "Mad Dog" nickname with a new one — "Moderate Dog."
Mattis is known as a moderating force in the administration, slow-walking Trump's directives and even ignoring the more incendiary ones.

For President Donald Trump, the luster seems to have worn off Defense Secretary James Mattis.

Trump heralded the retired Marine general when he was picked for the top job at the Pentagon at the end of 2016.

Trump praised him as "A true General's General" and has told donors, "The guy never loses a battle, never loses."

Trump frequently referred to Mattis as "Mad Dog" — though Mattis has expressed an aversion to that nickname, telling senators that it was given to him by the press and "perhaps they didn't get it quite right." Friends have also said that people who know Mattis do not call him "Mad Dog."

But reports have continued to emerge suggesting that Mattis is a moderating force in the administration, slow-walking Trump's directives and even ignoring the more incendiary ones. (And, on at least one occasion, defusing confrontations between administration officials.)

According to a Politico report, Trump has picked up on this dynamic and it has affected how he views the defense secretary. Behind closed doors, Trump has reportedly started calling the revered general "Moderate Dog" and might also be considering replacing him.

Mattis was not Trump's first choice for the job. But one of Trump's reported top choices, retired Army Gen. Jack Keane, and other national-security figures, like late Sen. John McCain, spoke highly of Mattis, who headed US Central Command before retiring in 2013.

Trump has reportedly been considering replacing Mattis for months.

A former senior White House official told NBC News this summer that Trump and Mattis "don't really see eye to eye."

Those comments came after Trump reportedly blindsided Mattis with his decisions to withdraw from the Iran nuclear deal, pause military exercises with South Korea, and create a sixth military branch focused on space.

While rumors about Mattis's fate have circulated for some time, the Pentagon chief is now expected to resign or be dismissed after midterm elections in November, according to Politico.

The White House is said to have a short list of potential replacements.

Two people reportedly on the list — South Carolina Sen. Lindsey Graham and Arkansas Sen. Tom Cotton, both Republicans — have indicated they aren't interested. Both are up for reelection in 2020.

Others under consideration include Keane, the former Army general, and former Missouri Sen. Jim Talent.

Trump and Mattis have both denied reports of a growing rift between them. In early September, when asked about Mattis's future after reports he had made disparaging remarks about the president, Trump said Mattis would remain.