John E. Sununu holds a commanding lead in the New Hampshire Republican Senate primary due to his strong name recognition as a former U.S. senator from the state, extensive local political ties through the Sununu family, and a substantial fundraising edge exceeding $3.6 million as of mid-2026. Polling consistently shows him far ahead of Scott Brown, a former Massachusetts senator and ambassador, who faces challenges as a perceived outsider despite prior experience in the seat. Minor candidates including Dan Innis, who has endorsed Sununu, and others register negligible support. The September 8 primary is approaching with limited recent shifts in positioning. A realistic challenge to the current trader consensus would require a major late development such as a strong debate performance by Brown, significant negative news affecting Sununu, or unusually high turnout favoring the challenger in the final weeks.