You can not have a genuine representational (or any other type) democracy with extreme concentration of wealth. Wealth is political power. Anything resembling genuine free enterprise can not survive with extreme concnetration of wealth.* Without democracy and protection of rights you are not free.
*Example: You want to open a store that competes with a chain store owned by an extremely wealthy person. That person and/or the corporation can use campaign donations and other methods of influence using money to get the government to prohibit that store from opening.