The simple answer is that minorities in any nation will most likely be respected by the authorities when there is a show of force by supporters of that group both locally and internationally. And your point is well made, we should continually support our people and their dire situations around the world.
Forced Sterilization in Puerto Rico
http://stanford.edu/group/womenscou...08/10/23/forced-sterilization-in-puerto-rico/
You can only surmise that the darkest ones were targeted and also wonder what happened to Argentina's black population. If we neglect to support each other we will likely disappear like the black men of Asia and Europe.