Jeff Sessions told the Senate Judiciary Committee 20 years ago that affirmative action irritated people (he meant white people) because it could cause them to lose opportunities “simply because of their race.” This sense of grievance lies behind the Justice Department’s recent memo seeking lawyers to investigate “race-based discrimination” in college admissions.

It also implies that all that stands between hard-working whites and success are undeserving minorities who are doled out benefits, including seats at good schools, by reckless government agents.

In fact, today’s socioeconomic order has been significantly shaped by federally backed affirmative action for whites. The most important pieces of American social policy — the minimum wage, union rights, Social Security and even the G.I. Bill — created during and just after the Great Depression, conferred enormous benefits on whites while excluding most Southern blacks.

Southern Democrats in Congress did this by carving out occupational exclusions; empowering local officials who were hostile to black advancement to administer the policies; and preventing anti-discrimination language from appearing in social welfare programs.

New Deal and Fair Deal initiatives created a modern middle class by enabling more Americans to attend college, secure good jobs, buy houses and start businesses. But in the waning days of Jim Crow, as a result of public policy, many African-Americans were blocked from these opportunities and fell even further behind their white counterparts. The country missed the chance to build an inclusive middle class....