The comment about McCain came the year after Trump joked with Howard Stern about dating and avoiding sexually transmitted diseases being like Vietnam combat. Three years before that in an interview with Stern, Trump said “that was a good job” of a Stern staffer having gotten out of Vietnam by claiming an apparently fake knee problem. And the whole dating-is-Vietnam claim wasn’t a one-off—in 1993, Trump said, “if you’re young, and in this era, and if you have any guilt about not having gone to Vietnam, we have our own Vietnam. It’s called the dating game.”
At other times, Trump tried to use money to make himself look like a champion of Vietnam veterans, contributing $1 million to build a memorial in New York City and $200,000 to sponsor a Memorial Day parade, in 1985 and 1995 respectively.
Trump’s reported past contempt for people in the military also lands close to home, in his own family. Trump’s older brother, Fred Jr., went into the Air National Guard, and, Fred Jr.’s daughter Mary Trump has said, “My father was frequently ridiculed for his career choices and disparaged for serving our country by both his father and by his brother Donald.”
Mary Trump also wrote in her book that when Don Jr. wanted to go into the military, his parents threatened to disown him.
Of course we also know about Trump’s public series of attacks on Gold Star parents Khizr and Ghazala Khan. And then there are the reports of Trump bellowing at top generals that they were “a bunch of dopes and babies.”
There’s a consistent through-line here, is the point. And, as several people who know him have observed, Trump’s feelings about people in the military line up with his emphasis on money and always looking exclusively for his own personal benefit. He is who he is, and that’s a wholly selfish person contemptuous of anyone not just like him.