For James Madison, the people of the several states were both the source of all power - and thus the ultimate solution to usurpations - but at the same time, the source of many of the problems due to the tendency towards factions - ultimately leading to the majority trampling on the rights of the minority.
The largest government in history is not even remotely close to the system the founders set up under the Constitution. Things didn’t get like this overnight - and there’s a root cause for why it’ll keep getting worse. Understanding it is to also understand the solution.