Mr. Pappas, a 44-year-old Democratic congressman, is the first major candidate to enter the race to succeed the retiring Senator Jeanne Shaheen.

Four-term Congressman Chris Pappas of New Hampshire has announced his bid to succeed retiring U.S. Sen. Jeanne Shaheen, a fellow Democrat, next year.

Former New Hampshire Gov. Chris Sununu’s (R) decision not to run for Senate is presenting a challenge for Republicans as they turn their sights on the state ahead of 2026. Sununu’s announcement was not necessarily surprising to Republicans.