The daunting task facing Democrats trying to win back the working class

Demonstrators hold signs while walking the picket line before Sen. Elizabeth Warren arrives at the United Auto Workers strike outside the General Motors Co. Detroit-Hamtramck Assembly plant in Detroit on September 22, 2019. | Anthony Lanzilote/Bloomberg via Getty Images

It’s perhaps the most urgent reason Democrats lost in November: The party has solidly lost the support of working-class voters across the country and doesn’t have a solid sense of how to win them back.

Now, a group of Democratic researchers...