John E. Sununu holds a commanding position in the Republican primary for New Hampshire's open Senate seat due to consistent polling leads exceeding 25 points over Scott Brown in surveys from early 2026, including a University of New Hampshire poll and RealClearPolitics average. His prior service representing the state in the Senate from 2003 to 2009 and House from 1997 to 2003 provides name recognition and institutional experience that Brown, a former Massachusetts senator who previously lost to the retiring incumbent in 2014, has not overcome despite his own campaign announcements and appeals to independence. Dan Innis withdrew earlier and endorsed Sununu, while other declared candidates remain marginal. With the September 8 primary still months away, traders' heavy weighting toward Sununu aligns with these established trends in voter preference and field dynamics.