Stefany Shaheen holds a commanding lead in the September 8, 2026, Democratic primary for New Hampshire’s 1st Congressional District due to her established name recognition as the daughter of longtime U.S. Senator Jeanne Shaheen, combined with endorsements from dozens of health care leaders, all Democratic mayors in the district, and early fundraising strength focused on medical research and cost issues. Maura Sullivan, a Marine veteran and former Obama administration official with prior congressional experience, trails as the clearest alternative but has not closed the gap despite recent platform releases on veterans’ affairs. Lesser-known candidates Carleigh Beriont and Heath Howard remain marginal in polling and visibility. Recent candidate filings and Shaheen’s campaign rollout have reinforced trader consensus on frontrunner status heading into the primary season.