Massachusetts Republican delegates awarded Michael Minogue the party endorsement at their April 2026 convention in Worcester, where he captured 70 percent of the vote and secured automatic ballot access for the September 1 primary. Brian Shortsleeve cleared the 15 percent threshold with 15.5 percent support to remain on the ballot, while Mike Kennealy fell short at 14.1 percent and suspended his campaign. Subsequent calls from state Republican National Committee members for Shortsleeve to withdraw have reinforced Minogue’s position as the consensus choice ahead of the general election against incumbent Democrat Maura Healey. Traders view the convention outcome and historical precedent—where no candidate receiving over 70 percent has lost the primary—as the dominant factors shaping current probabilities.