This didn't just happen, it was planned all along. The flood of immigrants was not primarily to gain democrat voters as they try to make you believe. It was/is about changing the composition of America from conservative white Christian to anything but!
Every civilization from the beginning has had slavery, in most cases through military conquest. America bought black slaves (who were sold by their own race) from Jewish slave ships but they are trying to portray America as the only nation to ever have slaves. America freed their slaves, unlike the nations before.
The white race is under attack, under threat of annihilation. That is why we have such a massive problem with illegal immigrants. That is why Hollywood and TV have been pushing race mixing as normal, even preferred. The white race is being brainwashed into committing suicide! Watch this video in which a Jew Harvard professor talks about getting rid of whiteness: