Is America a true Republican democracy?

The term 'republican democracy' is actually rather vague, and it has nothing to do with Democrats and Republicans. A republic is simply a government that is not governed by a monarch; a democracy is a government that is managed by the public.

The United States was originally designed as a "constitutional republic", where suffrage coexists with a constitution regulating the behaviours of the government. This is distinct from more pure democratic forms because the constitution is intended as ascendant over public will (barring the difficult and now abandoned processes of constitutional amendment).

Since the US Constitution is now treated by our political class as a series of nonbinding guidelines instead of as laws binding their actions, we are no longer a constitutional republic. It is now more appropriate to say that we are a "representative democracy". The public elects officials to exercise indirect control the government, and elected officials are kept in line by the threat of being voted out of office.