The reverse is largely true for the younger liberal writers and activists, many of them women and people of color, who have recoiled from Biden’s candidacy over the past several weeks. In a stream of articles and essays as he approached the race, these critics partly objected to Biden’s record over his long career, particularly on issues relating to race and gender. (One pressure point: his handling of Anita Hill’s accusations of sexual harassment against now–Supreme Court Justice Clarence Thomas in 1991.)

But even more fundamentally, many of them have rejected the idea that Democrats should prioritize a nominee who can win back working-class whites. They believe Democrats instead should find a standard-bearer who embodies and energizes their emerging coalition. “Democrats treat the working-class, white voter as if they were white buffaloes—sacred entities,” the New York Times columnist Charles Blow wrote this week. “I say that the rest of your base … are watching with dual lenses of disappointment and dissatisfaction.”

Biden’s kickoff campaign rally at a teamsters’ union hall in Pittsburgh on Monday left no confusion about how heavily his campaign will stress his claim to blue-collar bona fides. Biden thanked a long list of unions, plaintively asked when Americans stopped noticing the people who do manual jobs, repeatedly praised “the dignity of work,” and declared of himself: “I make no apologies. I am a union man. Period.” Apart from the presence of more African Americans in the crowd and Bruce Springsteen on the rally’s soundtrack, nothing looked or sounded very different than it might have if Hubert Humphrey had delivered the speech in 1968.

Part of the backdrop of the intraparty Democratic debate is the surprising results from the latest Census Bureau data on who voted in 2018. Those numbers suggest that the long-term decline of working-class whites as a share of the electorate appears to be accelerating. Over the past five presidential elections, non-college-educated whites declined from 54 percent of the total vote in 2000 to 44 percent in 2016, according to calculations based on the census data by the nonpartisan States of Change project. The erosion reflects a society growing both more educated and more racially diverse: Over that period, whites with at least a four-year college degree grew slightly as a share of the voting pool, from 27 percent to 30 percent of the vote, while minorities jumped from just under one-fifth of voters to more than one-fourth.

The latest census results tracked a much more rapid decline for non-college-educated whites from 2014 to 2018, according to an analysis of the findings conducted on my behalf by the University of Florida political scientist Michael McDonald, an expert in voting participation. In 2018, whites without a college degree cast just over 39 percent of the vote, down from 43 percent in the previous midterm election in 2014, according to McDonald’s calculations. That’s a four-percentage-point fall from one midterm election to the next, nearly double the average level of decline between presidential cycles since 2000. College-educated whites held steady from 2014 to 2018, at about 34 percent of the vote; nonwhites, meanwhile, surged from 23 percent in 2014 to nearly 27 percent last fall, McDonald found.