evidence: Though Trump once revered Mattis as "one of the most effective generals that we’ve had in many, many decades," their relationship had clearly drifted in recent months. Trump went as far as saying he was "sort of a Democrat" in an October interview. [...] Troops at the U.S.-Mexico border When the White House released a memo authorizing troops deployed to the U.S.-Mexico border to use lethal force, if necessary, against what Trump called an "invasion" of migrants, Mattis clarified that the troops wouldn’t even have firearms.