He said he's never registered as a member of any political party. And he's known as an intellectual, who would assign his underlings stacks of books to read.

Despite taking many positions opposite of Trump, Mattis seems to be highly revered by the active duty forces. I was reading the comments under a Navy Times article announcing Mattis's resignation. Lots of the folks were rooting for him to primary Trump in 2020, even asking about starting a GoFundMe page for him.

For a military man he was forward thinking.