He was a bright guy, but as he developed philosophy he also preached against democracy in favor of some kind of military dictatorship run by philosopher kings.

It seems like you're attributing the ideas in The Republic to Socrates. Of the Socratic dialogues written by Plato, some of them were fairly faithful representations of conversations Socrates actually had and others used Socrates as a fictional character to argue for Plato's ideas. The Republic falls firmly in the latter category.