Earlier quoted context omitted.
Additionally, it's important to note that modern day racism is more damaging to already marginalized groups or those that have historically suffered from it. In other words, a well educated Nigerian immigrant may not be damaged as much by the same level of racism as a Black person decended from slaves.
There exists an underclass in Ireland who have the same origin as the other Irish - but have many of the issues that exist in the African-American community. Live to about 50, developed a different dialect, very high crime rate - expected to be underestimated, constant violence, high domestic abuse, high illiteracy, very large families, living in squalor. Doesn't fit neatly into any faction's magic box of solutions.
As a society, we unfortunately discriminate against people based on lots of different factors.