Jeez another one of THOSE...
Look up the definition of Republic:
a state in which supreme power is held by the people and their elected representatives, and which has an elected or nominated president rather than a monarch.
And exactly how do we get our 'elected representatives'? We VOTE
And over the 200+ years we have gotten MORE democratic. Used to be only white men with property could vote. Then blacks could vote (except due to jim crow) and then women, then the voting age lowered to 18.
But every time we expand the franchise in order to work toward a more perfect union, people who spout garbage like "we live in a republic, not a democracy" enact laws to infringe on democracy. That is no coincidence