Because there was a difference between what the PEOPLE wanted and what the ELITES wanted.
The railroad barron needed cheap labour and didn't give a flying fuck about the KKK clowns marching in Washington.
The railroad barron needed cheap labour and didn't give a flying fuck about the KKK clowns marching in Washington.
The elites always want cheaper labor, while the existing domestic workforce usually opposes such measures (as it obviously devalues their labor)