The answer is: Jean-Jacques Rousseau
Most of Afro American were slaves until the end of civil war. After that they were struggling to have civil participation. The Civil Rights Act in 1821 encouraged many Afro American crongressman to talk about it. However, In the south the white Democrats terrorized black Americans with lynch mobs and instituted a convict system in which many Afro-Americans were forced to work free in mines, plantations, public work projects. Few Afro American had their own land. They were exploited as sharecroppers.
The renaissence came after a great migration from the south into the African American neighborhoods of the Northeast and Midwest.
The first important gate was the way that the congress members were elected. Before they started being elected through popular vote, framers made it so that state legislatures choose congress members because they believed that people couldn't be trusted with such a serious issue like choosing their government members.
The second was the introduction of the electoral college. They didn't think that people would be suited for choosing the president directly so they made the electoral college based on the population size to choose the president instead of the people themselves. This process got reformed over time as well to increase democracy.
