The SCOTUS is the ruling dictator (oligarchy). The other branches really don’t matter.
Perhaps you know that at the outset, Thomas Jefferson had already prophesied that this would be the result if the tenure of each Supreme Justice was for the remainder of one's life (revocable only by death, abdication by voluntary retirement, or by successful impeachment).
Never forget that the various decisions of this oligarchy are rarely of one mind, often consisting of a form of madness on the basis of irreconcilable differences.
If and when in the mode of operation judicial activism prevails, and dedication to preserving the original intent of the Constitutional provisions is lost, then that madness that overwhelms a justness will be the norm, and the condition of the state will no longer be based on the concept of freedom of choice of the governed individual constituent.
He/she will then have become a subject of the state, not a citizen able to freely follow a life of liberty and pursuit of self-interests.