That is just one form of democracy. There's a lot of works that discusses forms of authority and democracy and various ways of balancing the rights. One of my favourites on the subject is "After the revolution? Authority in a good society" by Robert A Dahl - particularly because it is short, clear and to the point.
But incidentally, your reasoning is the basis for Marx use of the term "dictatorship of the proletariat" - in Marx view, a state wielding power over one group against another is a form of dictatorship whether or not the group wielding the power has a majority or not.