Your claim that minorities have no power is just laughable. At all levels of government, from the federal to local levels, minorities are in positions of power.
To claim, as your image does, that there are more whites in political positions does not equate to "minorities have no power" instead it speaks to the reality that the white population is larger in numbers therefore it makes sense, from extrapolating out, that you would see more whites than blacks or Hispanics in political positions. Your argument is the same flawed argument ignorant people put forth regarding black actors being underrepresented in Oscar nominations and awards. They are not, in fact on a proportionate basis they are represented.