The military was supposd to be politically non-partisan.
As were the FBI, the Justice Department generally, the various intelligence agencies, and State Department. The Clintons co-opted all but State - which went political in FDR's time, if not earlier. GWB didn't clean out the Clinton operatives, and Obama advanced the politicization. From a big picture perspective, Trump has been stuck with the job of cleaning out the
Clintonian-Obamian Stables. And if he has at least some success, it might be among Trump's best successes.