It is my theory that the nationalist fervor Trump has so successfully tapped into can be traced directly to the debacle which the Vietnamese refer to as "the American war". People want to return to pre-Vietnam/pre-Korea America, the America whose "greatest generation" saved Europe from the Nazis ( the role of the Soviets lost to historical amnesia) and the Pacific from the Japanese. I believe this nostalgic yearning, articulated in Trumps slogan, taps into the subconscious grief and trauma and shame over the horror of that grotesque defeat in southeast Asia. It is a repressed grief we have never reckoned with as a country, despite the long black wall with all those names etched in it(50,000). The "conflict" (America never officially declared war) therefore continues to haunt the collective imaginary and manifest in endless "culture war" battles, patriotic zealotry and support for phallic, disciplinary Fathers like Trump. This is the more "immediate" cause, with the general acceleration of modernity and relativism of post-modernity being the background ambiance, as it were, for this dislocation/ alienation/ estrangement/anxiety (see earlier posts if you have nothing but time on your hands, which apparently you do if you are here).
It is hard to describe to those who weren't around for that insanity. Not just the napalm and body bags but race riots and campus revolts and feminism and hippies. This was a time when every household had a tv screen tuned to the nightly news and every one of those screens displayed a carnage that makes Trumps use of the word obscene. He has no fucking clue. Which is why John McCain despises the draft-dodging-silver-spoon licking puke with a depth I can't even imagine but, paradoxically, also why so many aging baby boomers see in him a redemptive, even transcendent erasure of that stain through masculine, hyper-aggressive re-assertion of dominance and authority. Psychic disturbance, big time.
The Super Duper Power with it's highly trained army and high-tech weaponry and endless resources got its ass kicked by a tiny but fervent anti-colonialist, revolutionary force of peasants and workers. 7 million tons of bombs (twice that of WWII) were dropped on Vietnam ,Laos and Cambodia and helicopters had to scoop people off the roof of the US embassy in Saigon as we fled in defeat. So making America "great again" would restore the pride of those who came home as losers, and in the mind of many ( not myself), as criminals. O
Of course the whole rust-belt/ working class/ endlessly looping Chevy truck commercial is a potent meme but the defeat is the under-layment that gives it real potency. That's my theory anyway.