The United States is substantively an oligarchic republic that has the superficial form of a rather distorted democratic republic (and representative democracy) and which likes to rhetorically appeal to democratic ideology, particularly as the entire justification for the government having any legitimate authority at all.
So, it isn’t a democracy, but it is entirely fair to criticize its failure to be one and insist that it ought to fix that proble, since its entire claim to legitimacy rests on it being a democracy as well as a republic.
> The United States is substantively an oligarchic republic that has the superficial form of a rather distorted democratic republic
Yes, it is a _representative_ democracy, as are most democracies around the world. We could be talking about the means to achieve such representation, and the legitimacy of such means, but by definition, it is still a republic _and_ a democracy, flawed or not.
These are not mutually exclusive. The US is a republic and a democracy.