That's not what he's saying at all. What he's saying is "If black people are an underclass in the US, then why did a majority of them vote one of the "underclass" in as President?"
Which I think is a valid point.
Could you see an Algerian voted in as President of France?
To be extra pedantic, Barack Obama ain't a classic African-American. His dad came to America as an immigrant.
Recent migrants with black skin seem to do much better than African-Americans who ancestors have been in the US for generations. Feel free to insert your own speculations as to why.
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?”.