Many hoped that the election of the first African-American President of the United States meant a decisive turn in the long and troubled history of race relations in the United States. And indeed President Obama’s election was a signal success for the American racial settlement of the 1970s. But at the moment of its greatest success, that settlement—call it the Compromise of 1977—was beginning to unravel, as evidenced by the fact that President Obama’s nearly four years in office to date have witnessed decades of economic progress and rising political power in black America shifting into reverse.

The race question is like no other in American life. From the beginning of the colonial era through the Civil War and up until today, American efforts to grapple with (or to avoid grappling with) the practical, moral, political and institutional consequences of race have shaped our political and institutional life. The Virginia House of Burgesses, the first elected assembly in the American colonies, assembled on July 30, 1619. In that same year the White Lion and the Treasurer docked in Virginia and unloaded the first African slaves to reach the present-day United States. Since that time, the stories of American representative government and race have been entangled in American history. The very structure of the Federal government and the nature of the party system were shaped by the slavery issue. The slavery question also shaped and ultimately limited national expansion. It affected the practical meaning of Federalism itself and the meaning of the rule of law. Nor is that entanglement yet over.

At every stage of American history, complicated political and economic compromises surrounded the question of race, each one managing it for a time but, despite the hopes of many, never settling it once and for all—not even by dint of a horrendously destructive civil war. The first of these was Compromise of 1787. The U.S. Constitution was written in a way that effectively banned Congress from interfering with slavery in the states, and the political interests of the slave states were protected further by the three-fifths clause as well as by weighted representation in the Senate and the Electoral College. On the other hand, that first compromise was shaped by the belief of many of the Founders, including enlightened slave owners like George Washington and Thomas Jefferson, that economic progress would before very long make slavery unprofitable and that gradual emancipation on a state-by-state basis would bring an end to this evil. Thus when Congress gained the power to ban the importation of new slaves after 1807, it exercised that power at the first opportunity with...