Michigan Democrats have spent years building one of the party’s most successful statewide operations, but Abdul el Sayed’s rise in the Senate primary is testing whether the coalition that powered those victories can survive the party’s deepening ideological divisions.

Ahead of Tuesday’s primary to replace retiring Sen. Gary Peters (D-MI), the contest between el Sayed, a former public health official, and Rep. Haley Stevens (D-MI) has become the latest and most consequential battle over the Democratic Party’s direction.