John E. Sununu holds a commanding lead in the September 8 New Hampshire Republican Senate primary due to his prior service representing the state in the U.S. Senate from 2003 to 2009, deep local name recognition, and consistent polling advantages over former Massachusetts Senator Scott Brown. Sununu has emphasized civility, fiscal discipline, and bipartisan problem-solving while securing notable support within the party, including from the Trump administration. Brown has highlighted his own Senate experience and independent positioning but trails significantly in surveys released in recent months. Minor candidates such as Chris Sununu and Dan Innis register negligible support. A sudden shift remains possible only through major late developments like a candidate withdrawal, ethics issue, or sharp change in voter turnout patterns before primary day.