Well there were points in American history where the sense that the nation was breaking apart were even more fervent than any time in the '70s.
There's no better point than in the 1850s and 1860s, when the nation actually did break apart and engage in a Great War that we just happen to call the Civil War. I'm sure there were many people alive at that point in time who believed that there was no future for the "United States of America" and that the USA would balkanize into multiple separate states, as it originally intended to.
Then there was the 1930s. Of course, the whole world thought itself to be in decline at that point. 1931-1933 was the only time frame in American history where a socialist or fascist revolution could feasibly have occurred Stateside. Far more likely than in 1968. Not to mention that the religious right in America was freaking the fuck out thinking the Antichrist had risen over in Southern Europe, what with Mussolini claiming to be restoring the Roman Empire. It's more surprising that there wasn't more unrest in the '30s.
The malaise and ennui that gripped America in the '70s and today are mostly due to a sense of stagnation and distrust in the political order. Most people online who support Donald Trump do so (mostly) ironically. There's definitely a conservative strain to their opinions, obviously, but almost no one takes the "God Emperor" claims seriously except liberals and the Left, as well as those Stormfronters who seriously do believe he's the White Protestant American Messiah.
For the rest of civil society, there's just no real sense of a future proper. While we're talking about automation and technological unemployment, they're talking about creating coal jobs. While we're talking about blockchain, they're staffing the White House with bankers.
There's renewed fears of nuclear war, to the point some are considering teaching their children about "duck and cover" maneuvers just in case. And there's a sense of societal moral decline due to the rapid spread of LGBT+ rights and marijuana legalization. More and more are fine with LGBT+ and weed, but the whole transgender bathroom controversy was apparently a step too far for some. That is, it seemed trivial. When it feels like the world is going to hell, the fact these blue-haired Millennials were screaming about letting transgenders choose which bathroom to go to seemed more like spoiled whining than an actual civil rights movement. The fact Donald Trump won the presidency wasn't a reaction to that, though.
I feel too many Trumpettes online are completely blind to reality in this case. Millions of people have not gotten over the fact that Donald Trump, a reality TV host, was elected president. They're just seeing "MAGA!" and red caps everywhere, blind to the fact millions are disgusted at how deeply entrenched entertainment has become in our society. These same types will unironically chastise anyone who claims someone like Kanye West could become president. It's literally a different reality for them.
The truth is, many people— liberals and conservatives— only see a reality TV host as being president. They wonder "who next? Will it be a reality TV star in 2020?" And yes, 2020. Get over it.
And yes, it probably will be someone even vapider than Trump in 2020. Get over that, too. Imagine a YouTube celebrity become our next president. That sounds ridiculous. But Trump becoming president was just as ridiculous last year.
If we could meme our way into Trump becoming president, who's to say we won't be saying "President Kardashian" or "President Hilton" in four years time?
That's another reason for this malaise. It was different with Reagan (the actor?!) because he actually was involved in politics decades before becoming president, so he knew exactly what he was getting himself into. People weren't shocked by it. If the Constitution were changed and Arnold Schwarzenegger became president in 2020, it would result in the same attitudes as with Reagan— he was an action movie star! Yes, but he was also a governor for 8 years.
Whereas with Trump, it's more like if Leif Garrett became president in 1980.
There's no respect for our executive office anymore. It feels like any hack celebrity could just flash da cash and get in the Oval Office for 4 years just for the lulz. That's not a sign of a healthy society. At least not to the population.
If a theatre star or bard with no political experience became emperor of the Roman Empire in the 400s, of course historians would cite that as being one of the reasons for the empire's collapse.
It's the zeitgeist of the era. It's one thing to fear such rapid changes; when the changes themselves beckon a response of "How the fuck did this actually happen?" repeatedly, people will instead insist that things aren't going well.
All we need now is a major recession, and everything will be as it was back then. We might not get lucky as we did in 2008, of course— it was only through the most desperate measures possible that the global economy didn't collapse. And I mean "collapse ", not just enter recession. People can sense something's not right with the economy right now; there's this artificiality to it all. We need to experience a recession just to clear it up. That'll be like a face-washing session. Either we clean our faces and realize that we're on the upswing once more, or we see our face has been eaten by some bacterial infection.