Washington periodically defers, as do Rome and Qom, to the judgments of the impressively robed — the ex cathedra portion of the political season.
I live in Rome and can assure Gerson that most Romans don't care what impressively robed people say in another country (the Vatican). I once saw an Italian politician say "sono ateo" (I am atheist) on TV. A few years later, he was prime minister. That couldn't happen in the USA (and not just because there is no office called "prime minister").
I will let residents of Qom speak for Qom.
I must say that the US approach to constitutional courts is preferable to the Italian approach in which only high officials have access to the constitutional court (Consulta) and that court gives orders to Parliament, so Parliament is bound by Parliament's interpretation of the constitutional court's judgment (just as it is in theory bound by the constitution). In practice both were ignored when they went counter to the business interests of Silvio Berlusconi.
So while I am not thrilled with the current US Supreme Court, I must admit that to have a constitution in practice as well as on on paper or parchment, one must have a supreme court and must give it the final word.