A pluralistic society guards against one group taking over by what?

Different ethnic groupps

A state of society in which members of diverse ethnic, racial, religious, or social groups maintain an autonomous participation in and development of their traditional culture or special interest, within the confines of a common civilisation. In a pluralist society, no one group or characteristic totally dominates social organisation because all groups have to act as if they value and accept diversity. In other words, pluralism guards against totalitarianism and against tribalism, though not against tribes asserting their separate identities, providing that they accept the equal value of other tribal cultures