Not sure how you can defend that belief. But you’re free to hold it.
Federalist Papers #10 mentions both a democracy and a republic, and clearly states that there’s a difference between the two.
John Adams wrote that a democracy is a tyranny against those in the minority.
You could kinda say we’re a “representative democracy,” in that we’ve elected people to represent our will. But even then, we are more a republic, bound to the Constitution and laws, and not bound to the whims of the democratic majority.
But whatever.
ff