Former Hartford Mayor Luke Bronin secured the Democratic endorsement for Connecticut’s 1st Congressional District at the May 2026 nominating convention, narrowly defeating 14-term incumbent John Larson by a 214-204 vote margin on the second ballot. This rare upset for a safe Democratic seat positions Bronin as the party favorite heading into the August 11 primary, where state Representative Jillian Gilchrest also qualified for the ballot. Larson has since shifted campaign messaging toward populist themes and criticism of outside influences. The convention results and subsequent ballot access have concentrated trader attention on the Bronin-Larson matchup, with lower-polling candidates remaining marginal in current assessments of primary voter preferences.