Why do some people insist that the US is a republic rather than a democracy?

Some people insist that the U.S. is a republic rather than a democracy to emphasize the system of governance established by the Constitution, which includes representative democracy and a framework of laws designed to protect individual rights and minority interests. They argue that a republic operates under a rule of law with elected representatives, contrasting it with direct democracy, where laws are determined by majority vote. This distinction is often used to highlight concerns about the potential for mob rule in pure democracies, stressing the importance of constitutional safeguards.