We arent talki g racial minorities, we are talking american cultures. Southern culture, amish terretories, mennonite terretories, etc. Its not about race, wrong sort of minority in this context.
The logic works fine, there are senators that represent those other areas and their culture, so its fine. We also balance that out in a different way, by adding a fixed number of sentators as a base and then addind more due to population. This evens out the densities in a similar way.