The USFG has been undergoing a long-term shift away from three coequal branches to an "imperial" presidency. Notably the White House is a lot smaller than the Capitol building (I should know; I've personally visited both), suggesting an original vision of a very much restrained presidency, but the former has since eclipsed the latter in importance. Like 80-90% of political discourse revolves around the President rather than Congress or the judiciary, or the states, and it can be said that some Presidents have enjoyed de facto cults of personality.
This probably started with Lincoln and the consolidation of Federal power that was perceived as necessary to win the civil war, then accelerated in the 20th century with the massive expansion of the military and welfare state, and finally there's the Second Trump Administration (albeit basically 100% of coverage thereof has a partisan slant to it, which makes an objective understanding of its workings difficult). I predict that even if the next President, be that Vance or a Democrat, makes a show of scaling these powers back, said reforms either won't be very substantial in practice or they won't last very long.
My position is that this present scenario was, in fact, always structurally embedded in the Constitution. Congress is a large body that, via parliamentary procedures, bicameralism, staggered elections, etc., gives its minority faction an effective veto. Likewise, polarization has broken down the longstanding mutual arrangements that for centuries have kept said gridlock to a manageable minimum.
The Presidency, in contrast, rests in the hands of a single individual. The President will never be gridlocked arguing with himself (not unless he happens to be schizophrenic, anyway), but is always in a position to make swift, decisive use of the authority legally available to him.
This both gives the President a long term advantage in consolidating power (re: he's fast and they're slow) and boosts the perceived legitimacy of him holding onto it. Because legitimacy, in practice, is a funny thing. Generally speaking people care about serious problems getting taken care of, and then they care about whether it was done lawfully. If they run into a scenario that the former cannot be had without dispensing with the latter, they will be tempted to accept that bargain. Polarization in Congress causes said unchecked problems to increasingly pile up, which makes the public increasingly willing to accept a more powerful Presidency to take care of them.
Is there a realistic solution to this? Probably not. Congress could clean up its act but in practice there's too much bad blood between the two parties to expect this. Nor is it realistic to expect that they'll vote to substantially curb the President's powers when both parties labor under the perennial delusion that they're one "great" presidency away from realizing every item on their longstanding ideological bucket list by four or five dozen acts of executive fiat.
If, in the 1780s, the Framers of the Constitution had designed a Bosnian-style presidency with multiple officeholders sharing power, a balanced government might've survived much longer but at the expense of a much slower response to wars or other national crises or disasters. Which would have the side effect of making for more powerful governors, who commanded state militias with a faster response rate, and by extension less of a need for a strong national army. Which, granted, may well have had the butterfly effect of "slavery was never abolished" or whatever.
