On my initial quick read, it seems to me that the California Supreme Court's cases (1) recognizing a right to same-sex marriage under the California Constitution, and (2) today, recognizing that Proposition 8 validly amended the Constitution and thus abrogated the right are excellent examples for any discussion -- in class or otherwise -- about popular sovereignty.

Three Justices reached a result different from the one that they had initially reached, based on their judgment that the people's views prevail over the Justices'. And they rebutted (in my view persuasively, but in any event clearly and informatively) the arguments to the contrary, both arguments focused on the revision vs. amendment question and arguments focused on the people's supposed legal inability to alter supposedly "fundamental" or "inalienable" rights. On the other side, there was able briefing to the contrary, plus Justice Moreno's partial dissent (which I've only skimmed at this point, though I'll read it later today). Put together, this seems to me a great case study of the recurring debates about popular sovereignty, constitutionalism, the role of courts, and more broadly the mixed majoritarian and antimajoritarian nature of American constitutions.