From what my dad tells me it began in the 1960’s and has devolved from then on. BTW, my dad is a Korean War and Vietnam War Vet with two Purple Hearts. One in each war.
He died recently and told me the proudest vote he ever cast was for Donald Trump.
That is kind of how I see it...it seems to me to have come to full fruition in the Eighties, because I didn’t get that sentiment fully until then, but I could see it.