Earlier quoted context omitted.
If you are not ethnically Chinese you are an underclass in Singapore. If you are not black you are not an underclass in the United States. I have no idea what it is like to be black in Singapore but for anyone else, I would think "not being an underclass" is high on anyone's list.
Doesn't having a popular black president in the US from 2008-2016 rather undermine the idea that black people are an underclass in the US? As opposed to being a group that on average have lower income than other groups in society? Couldn't assuming that any individual black person has low income or is part of an "underclass" be considered racist, in the sense of making judgements about individuals based on their skin…
Pointing to a country’s president as example of how black people are no longer underclass is akin to saying “he did it, why can’t you?”.