The Republican Party had run out of ideas but not out of juice, and its energy turned wholly destructive. Obama was so personally impressive and appealing that many Democrats failed to notice their party hollowing out like a rotten tree, losing majorities in Washington and across the country. Obama achieved one major reform, in health care, and he set a shining example of decent, grown-up government, but by the end of his presidency he was pleading with Americans to be better than we are. Something had gone wrong, in our economy and in our democracy, that Obama was unable to fix—that he might have been too reasonable to fully understand.

Read: The Obama doctrine

In the past century there have been only two realignments—one in 1932, the other in 1980. The first brought Franklin D. Roosevelt and the Democrats to power, and liberalism dominated until the late ’60s. The second brought Ronald Reagan and the Republicans to power, and conservatism retains its grip on our political institutions, if not on electoral majorities, to this day. “Every great cause begins as a movement, becomes a business, and eventually degenerates into a racket,” Eric Hoffer, the author of The True Believer, wrote. By the early 1970s, the New Deal coalition of urban machines and interest groups was becoming a racket, symbolized by piles of uncollected garbage in the streets of a nearly bankrupt New York City. Sure signs of degeneracy in the Reagan revolution appeared in the late 1990s, when Tom DeLay’s K Street Project erased the line between governing and big-money lobbying. The next step is dissolution, but the end of Hoffer’s life cycle can drag on for agonizing years.

The two realignments had several things in common. Long-term demographic change—immigration and urbanization in the first case, suburbanization and the end of the solid South in the second—reshaped the identity of American voting blocs. John the Baptists, harbingers of the realignment to come, appeared in unlikely forms. The failed candidacy of New York’s wet, urban, Catholic Governor Al Smith in 1928 foretold a changing Democratic coalition; the demolished candidacy of Arizona’s extremist Senator Barry Goldwater in 1964 signaled the hard-right turn of the Republican Party. When traditional politics failed to address chronic social ills, the rising activism of popular movements—industrial workers, evangelical Christians—pushed the parties toward new ideological commitments. Crises precipitated widespread unhappiness with the old order: the Great Depression in the early ’30s; stagflation, gas lines, and American hostages in the late ’70s. The midterm elections of 1930 and 1978 were like tremors before an earthquake. Then, in a decisive presidential election, a challenger came along to wipe out an incumbent, not just by winning more votes, but by bringing a new idea of government.