I don't disagree at all. He is a very real horror to our institutions. But:
(1) His tearing away the polite masks of Ryan, McConnell et al. and revealing the evil that lies beneath the Republican grand game is, indeed, part & parcel of how our very wily Framers set things up. To reveal to all with eyes and ears to see how the Republic may be going off the rails under any individual Administration; and to correct through subsequent electoral seasons.
(2) We always have the Third Branch, the Courts.
And even if DJT utterly compromises the Supremes for a generation, still the vast majority of cases get adjudicated at the, at most, Federal appellate level. Which retains its sanity, to now. And always will, as it is just too numerous and long-lived to be overturned by any one Executive.