The tension in the US system is between founders who believed in the virtue of the commoner and founders who feared mobocracy. At various levels of the system, the system is designed to be elitist. And the parties are fundamentally private institutions and can be as populist or elitist as they want (worth noting: in practice, the GOP constitution is more populist than the Democrat constitution, which is one of the reasons they nominated Trump; there weren't backstops in the GOP like superdelegates to push him off the ticket).

The Electoral College is often cited as serving a similar purpose... I think recent events show despite paying the consistent premium it extracts in elitist gatekeeping, when it finally mattered it failed to provide the promised protection against unethical demagogues.