In June, the ten-term congressman Joe Crowley lost the Democratic primary for New York’s Fourteenth District to a twenty-eight-year-old democratic socialist, Alexandria Ocasio-Cortez. This result was a shock to the Democratic establishment, who had thought of Crowley as a likely successor to Nancy Pelosi, the Party’s leader in Congress. Ocasio-Cortez’s win is a boon to the Party’s progressive wing, and it mirrors the rift between the moderate establishment once embodied by Hillary Clinton and the liberal insurgency championed by Bernie Sanders. Across the country, in voting booths and legislative chambers, Democrats are struggling to define a cohesive identity and to find a way forward. Benjamin Wallace-Wells provides a survey of some key midterm races and considers what they tell us about the direction of the Democratic party.