Anthony Constantino holds a commanding lead in the NY-21 Republican primary due to President Trump's endorsement, which has energized the party's base in this open-seat contest to succeed Elise Stefanik. As a political outsider and Sticker Mule CEO emphasizing business experience for economic development and manufacturing, Constantino contrasts with state Assemblyman Robert Smullen, who draws support from the state GOP apparatus, Conservative Party, legislative colleagues, and local officials through his legislative record and Marine Corps background. Recent developments include Jim Jordan's campaign stop boosting Constantino, ongoing early voting through June 21, and a series of debates highlighting differences on jobs, energy, and border issues ahead of the June 23 primary. Trader consensus reflects Constantino's momentum from the national endorsement amid a district spanning 15 upstate counties, though Smullen's institutional ties could sustain a narrower path if turnout favors party regulars.