Stefany Shaheen leads the New Hampshire 1st Congressional District Democratic primary field, reflecting her established name recognition as the daughter of retiring U.S. Senator Jeanne Shaheen and prior service on the Portsmouth city council. Multiple local mayoral endorsements and the first major labor union backing in the race have reinforced her position ahead of the September 8 primary. Recent candidate forums in late May highlighted shared Democratic priorities on housing, healthcare, and federal policy, while Shaheen maintains a fundraising advantage over competitors. Maura Sullivan, a Marine veteran and former Obama administration official with congressional experience, trails amid her own endorsements from national figures but less local institutional support. Lesser-known candidates Carleigh Beriont and Heath Howard show limited momentum or backing in the open-seat contest.