As intermarriage between ethnic groups accelerates—one in six Americans now marries a person outside his or her own race or ethnicity—the task of adjudicating these preferences becomes ever more baroque and absurd.

I once worked alongside a woman whose mother was a Cuban of partly African descent and whose father was Irish via Australia. Her first name was Latino, her last name was purest Hibernian. Preference? No preference? What about the children of an Anglo-Canadian multimillionaire and an African-American Rhodes Scholar, to mention another prominent example? Preference? No preference?

Both Puerto Rico and the Philippines were conquered and colonized by the United States. Yet migrants from the one commonwealth and their descendants receive legal preferences; migrants from the other do not.

Lyndon Johnson’s America was a country slashed by a color line of racial domination and subordination. Even the most affluent black citizen of the United States could expect to face humiliating economic and social discrimination. Meanwhile, the white majority overwhelmingly regarded itself as “middle class,” standing on a more or less equal footing with other “middle-class” whites.

Today’s America is a country whose class distinctions are growing as extreme as those in Edwardian England. Johnson’s assumption that non-black Americans all enjoyed more or less equivalent opportunities “to learn and grow, to work and share in society, to develop their abilities” seems poignantly out of date. A white skin may still correlate less with poverty than does a darker skin. But that skin alone long ago ceased to convey much in the way of privilege to the less affluent half of white America. It’s true, even Oprah can encounter rude treatment in a Swiss boutique. Day in, day out, however, William Julius Wilson’s prediction has been vindicated and more than vindicated: In 21st-century America, class trumps race.

In a grim irony, the mode of compensation that Lyndon Johnson urged in 1965 has itself become one of the prime instruments of class privilege in the United States.

If you are in a position in which affirmative action is relevant to your prospects, you have already risen above the worst that American society metes to its disadvantaged. Affirmative action is relevant to public-sector hiring and promotion, admission to selective educational institutions, and the upper reaches of corporate America. You don’t hear much about it for home-healthcare workers or prep cooks or security guards.

Lack of healthcare coverage, the huge overrepresentation of African Americans among the long-term unemployed, the stagnation of working-class wages, the collapse in household wealth in the housing crisis: These are the burdens that a contemporary Howard speech would properly address. They are not topics, however, that get much hearing in a country where the problems of the non-affluent command don't get much attention or interest from the political system.