The issue, perhaps, boils down to one of how perceptions or misperceptions of racial difference impact various individuals’, or groups of individuals’, experience of freedom in America. Some would argue that it goes beyond hampering their 'pursuit of happiness' to outright obliterating it.
What is key to America’s understanding of class is the persistent belief — despite all evidence to the contrary — that anyone, with the proper discipline and drive, can move from a lower class to a higher class. We recognize that mobility may be difficult, but the key to our collective self-image is the assumption that mobility is always possible, so failure to move up reflects on one’s character. By extension, the failure of a race or ethnic group to move up reflects very poorly on the group as a whole.