This ignores the trends that are going on in the rest of the world including Sri Lanka, Colombia, the Netherlands and Canada. It goes beyond the USA. The entire history of the 20th century can be summed up in one film: "Auntie Maime". In Auntie Maime, many outsiders (single mothers, LGBTQ, Jewish people and other minorities, artists and actors, care free liberals) who consider themselves well-off and elite, resent that they've been excluded by the traditional Republican white shoe/big business upper class, who look down on them. The struggle of the 20th century was these distinct well-off groups (for other examples, see the Cosby Show, Will & Grace, Modern Family) achieving recognition as part of the elite. However, these elite left other groups (working class people of all races) outside the tent of respectability. What's more is this new elite had a lot more in common with the old elite than they did with those outside the tent: a globalist vision-- one where borders are no longer as important, where trade is free, where nations cooperate to police the world, where capitalism protects the interest of the well-off but provides a moderate social safety net, and where certain social issues near and dear to them are prized, and where expertise is valued above all. It's where the EU was born, and why the EU is drifting (now with the weight of Brexit thrown off) into ever greater unity (particularly now with the Russian threat).
But those outside the tent had a distinct feeling that they were normally being thrown under the bus (with rules such as with respect to COVID and climate change applying to them, but not their elitist betters) and were being looked down upon (the Obama guns and religion remarks). So, there are two temptations for them to overthrow the world globalist elitist order: a) socialism: think Bernie bros or the socialist wave sweeping South America, under the idea that the previous models weren't true democratic socialist models, and b) populism (which is why they like Trump so much...not only does he fight back, but unlike DeSantis, Trump is loved because he's been treated like an outsider just like them).
I agree superfederalism in a very loose EU like confederation would fix this. But there are two problems with that. 1. the EU itself (like most institutions) tends to drift to greater centralization and greater unity because the power holders like to amalgamate and enhance their rule, and 2. the globalists will never agree to it: there are too many changes they regard as existential whether climate change, abortion access, COVID rules, or their own social status, which this type of arrangement would overcome. My worry is that we are headed to a lot more Sri Lankas, a lot more Canadas, and a lot more Netherlands. It's actually kind of funny that it started in Canada: we see the globalist reaction that will happen and eventually it just fizzled (the Canadians are so nice of a people, after all). I fear Sri Lanka is really just the first domino to fall, and given what's coming, we are going to see a lot more of it.