I've seen this one happen enough times that I feel it might just be safe to call it from the hip. But this is assuming that the US political system in its current raggedy-ass form survives another 4 or (lawd help us) 8 year cycle, turning over power in a manner we've deemed recognizable for the last couple of decades.
What I'm referring to is this: yes, the contradictory pressures that the feckless Democrats produce in their activities does eventually build up enough force to carry those waves of discontent that sweep the Republicans back into power, but then after the GOP is in and smashing everything up, folks eventually get tired of the bull-in-the-china-shop routine and vote the Democrats back in.
But what often happens is that as that smashing and flailing has gone on, things open up and change enough that the Democrats look at it and realize, "oh wow you can actually do that," and so they timidly try some of that smashing themselves, at least a little more quiet-like and politely, and they might clean up the worst of the mess in the process to maintain some propriety.
I've experienced this directly in demolition, of all activities. I'm gingerly pulling at a slat of wood with a hammer claw, trying to pry up the nails while trying to keep everything intact, and someone with more experience than me walks up and says, "No no time is money here gimme the hammer, just pull it this way and smash it that way like this, and if that doesn't work take the hatchet and chop it like this, and if that doesn't work saw off the nails with a hacksaw or a grinder wheel like this..." and so on. And then once I saw someone else do the thing, and knew what was possible, and had a clearer idea of what the objective was, I could be a bit more aggressive with the demo and actually get things done.
The problem with this analogy though is that here we are talking about a circumscribed job site with a clear objective governed by people who know what they are doing and what results they are after. In a certain sense the political class does know what they are doing in order to get ahead in a certain limited environment and paradigm. But then what is the objective? Where is it all going? And what does it mean to be successful when your success is decoupled from any sort of halfway "objective" measure of political and economic health of the political body that you're serving?
In the modern era, what passes for that measure seems to be yoked to the movements and operations and preferences of capital, with global governments attempting to ride that tiger while at the same time making appeals to it and attempting to steer it in each nation's particular interest.
So in the US, the Democrats proceed to quietly continue a lot of the pioneering Republican policies, shedding the excesses and slapping their trademarked smiley face sticker back on the faceplate. But of course these cycles occur within larger cycles themselves. We've been seeing this dynamic since the Reagan era at least, and then before that we had the thunderclap of the FDR regime and the New Deal, whose own particular decaying echoes graced the land for some time, until subsequently collapsing into the Reagan era.
In our present cycle, a lot of the effort of the political class consists of getting all of the protestations and creaks and cracks and screeching metal and other grievous noises to shut up as they continue to dismantle what is left of organized labor and the regulatory state set up during and after the World Wars, so that they and their buddies in the oligarchy could get bigger and stronger and loot better and quicker.
And this is a continuation of the larger neoliberal project, but which is shifting over into something new. It can't all be demolition, as fun and satisfying as that can be. Eventually you have to clear out the wreckage and plant or build something nice. But in this case there is a whole lot of material to demo, and there is still a whole lot that can be taken apart, and that seems to be the only thing any of these people really want (or know how) to do. And you usually have to have something nice or somewhere nice to start from, where the nice stuff comes from to build the nice things somewhere else. What do you get when you trash all of it? And then keep on trashing? Just more trash. And then eventually when it does come time to build - and we are seeing this in an embryonic form now - you just build nice heaps of garbage made out of trash.
The political class has been getting so high off of their own product for so long, and we've been moving collectively through these gargantuan trauma cycles for so long, which are difficult to comprehend clearly as individuals, that it has become difficult to establish any kind of productive collective goal or direction, beyond what gets articulated with the most force as countless factions struggle to assert their own distorted visions, making their own desperate attempts to make a mark when they have the power.
And in this self-referential, cyclical churn, you may have various political and economic problems addressed incidentally (while multitudes more are produced) as the various self-interested actors tackle their respective pet projects for prestige, favor, and treasure, and the system continues to evolve in the direction of least resistance, as it were, but without a larger guiding direction, it is difficult to tell where the greater churn will end up, and what sets of consequences result from that.
I should qualify though: there is a general direction that can still guide national politics in the US, depending on what is still possible, given where the power is flowing and concentrating, and that's down and apart. Sure, we have some great rock-n-roller types coming out of local politics and local activism, which could take quite some time to manifest at larger scales. But national politics? Put a fork in that one, as they say.