True democracy basically means mob rule. In other words, whatever the majority decides, goes, regardless. If right handed people (the majority) decide left handed people should be forced to become right handed, or jailed, that would be the law.
The United States, and most states, is a Representative republic. Meaning everyone, even those in the minority, have equal representation. People in a certain geographic area elect one person in the state, or U.S. House of Representatives (early on called the peoples house) collectively, they, not the majority, determine state (or federal law)