Is This the End of the White Working-Class Democrat? Democrats hoped to lose by less in blue-collar areas that had drifted toward Donald Trump. In many places, they may have lost by more.

In Ohio, Senator Sherrod Brown, a longtime champion of working-class voters, was toppled by a rich Republican former car dealer. In Washington, President Biden must now hand back power to Republicans and surrender leadership of a party increasingly dominated by highly educated voters. And in Pennsylvania, Senator Bob Casey, whose family name has for years been synonymous with white working-class Democrats, is confronting the real possibility of defeat. Eight years after fury among white working-class voters propelled Donald J. Trump to victory, Democrats swore that this time, they would try to do better with that group. Instead, the party’s staggering...