Stefany Shaheen holds the lead in the September 8, 2026, Democratic primary for New Hampshire’s 1st Congressional District, with traders assigning her a roughly 60 percent implied probability. Her name recognition as the daughter of longtime U.S. Senator Jeanne Shaheen, combined with endorsements from every Democratic mayor in the district and a strong recent fundraising quarter, has solidified her position. Maura Sullivan, a Marine veteran and former Obama administration official who previously ran for the seat in 2018, maintains second place on the strength of her overall cash raised and national security background. Carleigh Beriont and state Representative Heath Howard trail further back, reflecting limited name identification and narrower donor bases. Earlier university polling showed Shaheen ahead, though the race remains months from the primary and could shift with additional debates or late endorsements.