Myron Magnet summarizes the history of the decay of the US Constitution. Even the founders thought that might be inevitable, given their wisdom about human nature, but they did their best to provide roadblocks. Securing the blessings of liberty (from government, of course) and securing defense from exterior powers...
There is always the excuse of a reason: Security, or To Do Good.
It’s Not Your Founding Fathers’ Republic Any More - Presidents, Congresses, and courts are creating an elective despotism.
... we had better understand just what happened. There’s no single villain. As these books show, all branches of government conspired over more than a century to turn the Constitution that the Framers wrote in 1787, plus the Bill of Rights that James Madison shepherded through the first Congress in 1789 and the Fourteenth Amendment ratified in 1868, into something their authors would neither recognize nor endorse.