Proportional representation, widely adopted in Europe in the first decades of the 20th century, was never embraced by the US because it is a system that would allow black representatives to be elected regularly.
La representación proporcional, que se adoptó ampliamente en Europa durante las primeras décadas del siglo XX, nunca se aplicó en los EU, porque es un sistema que permitiría que regularmente resultaran electos representantes negros.