It depends on how you define "democracy". We're clearly not a pure democracy. Plus we have some restrictions on who can participate in the governing of our polis.
But I hope you disagree with those who claim that the USA isn't a democracy, but a republic.
Depends on how you define "democracy" . We're unambiguously a republic. The Constitution even requires the States to have a republican form of government. However, it's only politics that keeps us from returning to a plutocratic form of government with formal property requirements to vote and/or hold office. We still have some plutocratic elements in our mostly democratic republic.