John E. Sununu holds a commanding lead in the New Hampshire Republican Senate primary due to his prior service representing the state in the U.S. Senate from 2003 to 2009, deep local roots as a longtime Granite Stater, and substantial fundraising edge exceeding $3.6 million. Recent polls, including those from the University of New Hampshire, confirm his strong advantage over Scott Brown, a former Massachusetts senator and 2014 New Hampshire nominee who brings name recognition but limited in-state ties. The September 8 primary date leaves limited time for challengers like Dan Innis or others to close gaps. While the market consensus implies high certainty, late developments such as major endorsements, candidate health events, or shifts in voter turnout could still alter outcomes before ballots are cast.