While contemplating the degradation of America's political institutions, I thought I'd jot down a few thoughts about where we've been and where we seem to be headed.
There are three fundamental principles of American representative democracy. The first two are descriptive, the third is aspirational and protects against the tyranny of the majority. Those principles are: the people are sovereign; the people exercise their sovereignty through elected representatives; and the majority cannot harm the minority.
The first principle is an abstraction that requires a mechanism for realization. The second principle is that mechanism. It requires rules to fairly implement, and it assumes fair and even implementation of the principle is desirable and possible. The third, simple enough on its face, is at once highly problematic and absolutely necessary. In its absence, as noted above, democracy is simply a tyranny of the majority. We have struggled, often violently, over the third principle for all of our history.
For two centuries the majority rationalized its unceasing harm of the minority. The majority now correctly perceives its inevitable transition into the minority, and it suddenly insists on a perverse application of the third principle, that protection of the minority should equal ascendence of the soon-to-be minority over the emerging majority. (By the way, that application is similar to protections John Calhoun sought in antebellum America for an increasingly politically outnumbered slave-owning class.) Additionally, that application, many in the fading majority hope, will result in de facto and de jure permanent minority status for the emerging majority.
Three institutions, one informal, one formal and largely immutable, and one formal and subject to only those changes it is willing to undergo, are manipulated for the long-term benefit of the fading majority: redistricting, the electoral college, and the Senate. SCOTUS can eliminate the gerrymandering that occurs under the first; the states can eliminate the second; and only the Senate can reform itself. If none of those reforms happen, our representative democracy will continue on its present path and eventually resemble South Africa under apartheid.
What, if anything, happens after that is a crapshoot.