John E. Sununu holds a commanding lead in New Hampshire’s Republican Senate primary, scheduled for September 8, reflecting consistent polling margins of 35 points or more over Scott Brown since early 2026. As a former U.S. senator with deep state roots and family political prominence, Sununu benefits from strong name recognition, local endorsements, and backing from national Republican groups that have spent millions in support. Brown, a former Massachusetts senator and ambassador who previously ran in the state, trails due to comparatively weaker voter familiarity and appeal among primary voters. Minor candidates including Dan Innis and Chris Sununu have not mounted viable challenges. While late shifts remain possible ahead of the primary, the sustained polling gap and institutional support underpin the current market consensus.