Why do some people hold that the united states is more properly called a republic rather than a democracy?

"In republics, citizens have less direct control over government. ... (c) Why do some people hold that the United States is more properly called a republic rather than a democracy? In a Democracy there is no need for a Constitution, since the majority can simply change Law at a whim."

From google

List the sentences. keep in mind when you use sarcasm you are saying one thing in a tone to make it clear you are joking. like for instance, pretend you get a math test from your teacher. you’d most likely say, “oh yay.. a math test.” but you’d have the tone to give it the “oh come on” feeling. does this at all?