I still don't get how Boomers (and a bit of the Silent Generation) were super left wing in the 60s, but by the 80s or even the late 70s they became super right wing. Not sure if it's just a USA thing or not, either.
Because they weren't. There was a vocal minority who was super left wing in the 60s, but the huge majority were as reactionary and conservative as they are today. Hippies weren't really representative of their generation, they are just the most iconic. Remember that Nixon not only got reelected, but reelected with a landslide.
I don't know how many people think this way, but I once heard a quote: "If in your youth, you don't vote left, you don't have a heart. If when you're older you don't vote right, you don't have a head."
I don't think that quote says anything good or true, but if there are a lot of people who think that way, well...
That quote has been changed a bit, but in it's original form I think it was Churchill.
And the general idea is that as you age your idealism is tempered by practicality, as well as having adapted to the situation and built something of a life of your own, so you've gradually moved from the camp of "very little to lose/give up in exchange for all these benefits" and toward the camp of, "you know what, I'm doing okay, I've figured out a way to make it work, and I'd rather 'the system' just leave me alone at this point, since I'll be footing the bill for things that aren't even going to benefit me that much".
Obviously it's a lot more complicated than that, but that's the gist.
It's also worth remembering that "liberal" and "conservative" meant something different mid century than they do now. Especially with the MAGA influence.
I think the shift in political affiliation had something to do with Regan and the de-regulation of many different business sectors by the republicans in the 80's and 90's.
It became 'easier' to make money and with lower taxes those people got to keep more of it (at the expense of other Americans). So as these boomers started getting out of college in the late 70's and 80's they could now become stock brokers, bankers, real estate brokers, etc instead of a 9 - 5 factory worker. And those were the industries that were getting a lot of lower regulations from republicans so why not vote for their best interest and leave the left wing ideals to someone else.