In the humid August heat of a Michigan primary, Democrats cast ballots that amounted to something more than a choice between two candidates — they were asked to decide what kind of party they wished to inhabit. Abdul El-Sayed, a progressive physician, held an early lead over establishment-backed Representative Haley Stevens in a race that crystallized the Democratic Party's unresolved tensions over economic populism, the influence of money in politics, and a rapidly shifting consensus on Israel. Michigan, a presidential battleground with one of the nation's largest Arab American communities, o