As the party’s attention turns to the presidential nominating season, one of its biggest challenges will be navigating this culture war in its own ranks. The energy at the moment is with the liberal wing, centered around cities and college towns and on the coasts, its members mostly white and college-educated and far to the left on social and cultural issues compared with the rest of the party. But its voting majority is still more blue-collar and diverse, many of whom favor an incremental approach on social issues and who are more interested in preserving the clout of longtime powers like Crowley and Capuano than in notching symbolic victories for the “resistance.”

In many of the cases outlined above, the policy differences between the candidates are microscopically small. Nearly all Democrats favor tackling income inequality, raising taxes on the wealthy and the minimum wage, and reforming the criminal justice system. There is some dispute over how fast to move and how far to go, but the broad outlines are the same. The differences, in one analysis, are stylistic, and so it is easy to imagine that they will be worked out over the next year as the party settles on another presidential nominee.

But there remains another possibility: that the split will prove to be more fundamental, that the party’s diverse base and its growing share of college-educated voters don’t have the same values or the same amount at stake—and that as Americans increasingly self-segregate, and even left-leaning elites close the gates of privilege behind them, that the party’s wings will drift too far apart to unite behind anyone.