A role model in the flesh provides more than inspiration; his or her very existence is confirmation of possibilities one may have every reason to doubt, saying, "Yes, someone like me can do this."
One thing has not changed: to doubt the worth of minority students' achievement when they succeed is really only to present another face of the prejudice that would deny them a chance to even try. It is the same prejudice that insists all those destined for success must be cast from the same mold as those who have succeeded before them, a view that experience has already proven a fallacy.