It starts innocently, like repeal of the 17th amendment by progressives in the name of greater democracy...which opened the door to an unchecked growing national government.
It takes form with things like FDR's court packing scheme, which enabled later abuses of the Constitution under cover of a new interpretation of the catch-all commerce clause that nullified the enumerated powers aspect of the Constitution.
Reid's undermining the tradition of the filibuster also opened the door to later abuses of tradition.
Those were innovations by the Left to remove restrictions on doing good. I have always pointed out that restrictions also restrict evil, and it would take someone evil to demonstrate this. But, I don't think the Left has learned its lesson. Instead of wanting to return to resonable restrictions, they have merely enhanced their efforts to exert a death grip on power. It won't end well for the Republic.