Yet 2016 offers reasons for unique alarm. The progress of recent decades, both political and social, appears to have evaporated in the past few years. And the problems, as so often, are focused on the two oldest classes of our Poor. These two underclasses pre-date the United States as a political union. 

The black underclass, brought here in chains, toiled for centuries in the hopes of earning freedom — first physical, then political. They found themselves concentrated in the South — the home of King Cotton. The white underclass, many of whom descended from Scots-Irish peasants of the motherland, came here freely. They tended to concentrate in the rural parts of the eastern United States, especially along the Appalachian Mountains. The paths of these tribes have sometimes intersected. When recently freed slaves began to marry the white indentured servants of Virginia planters, their children took on a color that entitled them to all of the burdens of their darker-skinned parent. So they moved to eastern Kentucky and eastern Tennessee, called themselves Cherokee Indians, and attempted to live in peace. The locals, unsure what to do with their new neighbors, derisively called them“Melungeons.” “

 A century later, as the industrial economies of the North created millions of new jobs, the white and black underclasses went hunting for opportunities. The black folks encountered a spate of indignities and a government housing policy that forced them into artificial urban ghettos. And the white establishment, confronted for the first time with people who looked like them but possessed none of their sensibilities, treated these seemingly foreign whites with scorn. As anthropologist John Hartigan Jr., commenting on the rapid industrialization of Detroit, has observed: It was not simply that the Appalachian migrants, as rural strangers “out of place” in the city, were upsetting to Midwestern, urban whites. Rather, these migrants disrupted a broad set of assumptions held by northern whites about how white people appeared, spoke, and behaved. . . . The disturbing aspect of hillbillies was their racialness. Ostensibly, they were of the same racial order (whites) as those who dominated economic, political, and social power in local and national arenas. But hillbillies shared many regional characteristics with the southern blacks arriving in Detroit. 

In the face of these pressures, the two groups took different approaches to politics. The white poor, unencumbered by legal discrimination, focused on a politics of class. From Jackson to Truman, they voted their pocketbook, taught their children to mistrust the rich man, and hated the elites who looked down on them. 

As Martin Luther King Jr. observed shortly before his death, they benefited psychologically from the caste system in the South. Black people, meanwhile, understandably voted the color of their skin, putting their trust in whoever promised to tear down the most legal barriers. Sometimes, as with Lyndon Baines Johnson, these interests aligned, delivering supermajorities in the process. But those moments were largely the product of chance. 

The civil-rights successes of the 1960s were supposed to change that. In 1978, the eminent sociologist William Julius Wilson argued confidently that class would soon displace race as the most important social variable in American life. As explicit legal barriers to minority advancement receded farther into the past, the fates of the working classes of different races would converge. By the mid 2000s, Wilson’s thesis looked pretty good: The black middle class was vibrant and growing as the average black wealth nearly doubled from 1995 to 2005. Race appeared to lose its salience as a political predictor: More and more blacks were voting Republican, reversing a decades-long trend, and in 2004 George W. Bush collected the highest share of the Latino (44 percent) vote of any Republican ever and a higher share of the Asian vote (43 percent) than he did in 2000. Our politics grew increasingly ideological and less racial: 

Progressives and the beneficiaries of a generous social-welfare state generally supported the Democratic party, while more prosperous voters were more likely to support Republicans. Stable majorities expressed satisfaction with the state of Race Relations. It wasn’t quite a post-racial politics, but it was certainly headed in that direction. But in the midst of the financial crisis of 2007, something happened. Both the white poor and the black poor began to struggle mightily, though for different reasons. And our politics changed dramatically in response.