That should be enough for anyone; the concept could not be simpler. Yet, deep within the American subconscious, there still resides the need to categorize and catalog, to provide some sort of delineation as to where any particular person falls. Though the Constitution would count all Americans as equal, subject to the same laws, awarded the same rights and privileges, free to live in perpetual liberty under our flag, some find it necessary to divvy up freedom and partial it out based on sometimes arbitrary and mainly discriminatory grounds, as if some are owed a greater degree of it than others.
When you can subject people to categorization, it is easier to minimize and dismiss their attitudes, their questions, their concerns, and their objections. It is also easier to foist upon them stereotypes, that can easily justify your negative view of the group. Why take a person as they are, when you can tar-and-feather them with a broad brush? Lumping them together with their "disreputable" counterparts allows you to assuage nagging guilt and reinforce your own superiority. Such self-fulfilling and self-serving schemas ensure that everyone is in their proper place. This allows "real" Americans to distance themselves from the rest of us.
While pride in the heritage of our ancestors is not to be dismissed, it cannot become the yardstick by which we are measured. To be African American, Indian American, Vietnamese American, Italian American, etc., is only important in terms of that heritage, not as a means to erect fences around groups. Each and every American, regardless of heritage, wealth, education or employment, deserves the same level of respect and decency, the same full and total access to liberty and justice, and the same right to pursue prosperity.
Anyone who wishes to wrap themselves in the American flag and the Constitution, must first accept that they have no greater claim to those things and what they represent, than anyone else who is an American citizen. This country is strong through its diversity, not just in people, but in ideas; those who journeyed here over the centuries brought with them hopes, dreams, aspirations, innovations, and a desire to be free, and we are the caretakers of that spirit. America stands or falls through all of us, not just a select few; it is up to every one of us to do our utmost to maintain the freedom and liberty of all of us. That is what should define a real American.