When McCain died, in August 2018, Trump told his senior staff, according to three sources with direct knowledge of this event, “We’re not going to support that loser’s funeral,” and he became furious, according to witnesses, when he saw flags lowered to half-staff. “What the fuck are we doing that for? Guy was a fucking loser,” the president told aides. Trump was not invited to McCain’s funeral.
Again, Trump’s base are the same people who fly multiple POW/MIA flags on the back of their trucks; the knots they tie themselves in to defend the guy make no logical sense. The Atlantic goes in to detail about how Trump thinks Americans who died serving their country are “losers” and “suckers”. This quote is also telling:
Belleau Wood is a consequential battle in American history, and the ground on which it was fought is venerated by the Marine Corps. America and its allies stopped the German advance toward Paris there in the spring of 1918. But Trump, on that same trip, asked aides, “Who were the good guys in this war?”