Inequality and Democracy

The relation of competition and inequality. And the relation of inequality and growth. Both are much stronger than commonly recognized, but neither is as mysterious as the relation of inequality and Democracy.
The western social order is based on Free Market Economy and Democracy. Free markets, while supporting growth, create and feed inequality. To balance them out, there is Democracy, for the society to have the final say on the economy, indirectly but decisively. Based on absolute-political-equality, where each individual has one and only one vote, Democracy should be able to contain inequality within rational and acceptable boundaries.
How come, then, many western societies are witnessing the strange co-existence of excessive-inequality and Democracy in practice, although they are supposed to be mutually exclusive in principle?

Inequality and Democracy explains why the welfare of the society can be maximized only through a delicate balance of growth and inequality, how Free Market Economy and Democracy are supposed to bring out that balance through the theoretically flawless check-and-balance dynamics between them, why these dynamics fail spectacularly in practice, creating too high inequality and too low growth, and how a society with adequate Social Intellect can deal with inequality through Democracy to cure the troubles.