There has always been a meddlesome quality to the USA that the rest of the so called developed world turned a blind eye to. Along the lines of 'their bastards, but at least they're our bastards'. Of course that does not make it good, but the balance calculation worked out in favor of toeing the line and being careful not to get pulled out of joint too much. 9/11 changed all that and effectively Bin Laden forced the USA to lower its mask for long enough that the world could no longer ignore the bad sides of Uncle Sam. Even that would have not been enough to seal it, but Trump has managed to accomplish this in record time.
I think that a big part of it is the transparency brought on by the vast communication bandwidth that came online starting after the dot com years. This stuff happened before just the same, but was concealed by media gatekeepers.
Bay of Pigs, regime changes all over including Iran, South Asia wars, Afghanistan (not the recent one, the one in the 80s), all the cold war stuff, etc etc.
It's the two party system. If liberals are okay with 'pro lgbt muslims' and say things like 'gang violence isn't a problem' then people no longer vote for liberals.
Trump doesn't have popular support. Many of his 2024 voters are furious with him.
What Trump has is oligarch support - an unholy alliance of weird and cranky tech billionaires, old(ish) money, foreign money, media owners, and insane white supremacist patriarch-wannabes, some of whom operate through think tanks, some through megachurches.
The media are doing an excellent job of normalising this, not least - but not only - sanewashing Trump's obvious mental and physical decay.
I want to believe this desperately, but from what I see (well, on YouTube videos, surveys and polls) it makes it very hard for me to do so. I still see massive endorsement from the not so well to do in the hinterlands.
I will however grant you that my sampling is no where close to uniform.
There has always been a meddlesome quality to the USA that the rest of the so called developed world turned a blind eye to. Along the lines of 'their bastards, but at least they're our bastards'. Of course that does not make it good, but the balance calculation worked out in favor of toeing the line and being careful not to get pulled out of joint too much. 9/11 changed all that and effectively Bin Laden forced the USA to lower its mask for long enough that the world could no longer ignore the bad sides of Uncle Sam. Even that would have not been enough to seal it, but Trump has managed to accomplish this in record time.