It might be most useful to think about ‬young progressives as a third party trapped in a two-party system. Radicalized by America’s political sclerosis and economic and social inequality, they are a powerful movement politically domiciled within a larger coalition of moderate older minorities and educated suburbanites, who don’t always know what to do with their rambunctious bunkmates.

What would this progressive third party’s platform look like? In one word, justice: Social justice, sought through a reappraisal of power relationships in social and corporate life, and economic justice, sought through the redistribution of income from the rich to the less fortunate.

One can make out the contours of this agenda in “Hidden Tribes,” a 2018 study of the political views of 8,000 Americans, which sorted the country’s voting-age population into seven political groups. The study called the youngest and most left-wing group in the survey Progressive Activists. They accounted for 8 percent of the population and as much as one-third of likely voters in the Democratic Party, due to their higher-than-average engagement in politics. (I don’t want to imply that Sanders voters and the Progressive Activist tribe are synonymous: The demographics of Elizabeth Warren’s support suggest that she attracts a large number of Progressive Activists too.)