What part of: I pledge allegiance to the Flag of the United States of America, and to the Republic for which it stands, one Nation under God, indivisible, with liberty and justice for all, do you not understand?
A democracy is mob rule. What the majority wants, they get, meaning, if 51% of the people want to take your property, they can take it.
The word 'REPUBLIC' comes from the Latin Res Publica, meaning, the public law, or, the law is the thing, referring to the fact that our society is based not on the majority rules, but on LAWS. That way, even if the majority want your property, the law protects you, and we are guided by a set of rules we all agree with and adhere to, thus we are a Republic. A Constitutional Republic.
Besides, there are no true democracies; careful study reveals that democracies are only a transitory state, and they all eventually transition into an oligarchy.