Incumbent Republican Brian Mast holds a structural edge in Florida’s 21st district, where he won by 23 points in 2024, anchoring trader consensus on a Republican victory by double digits. Democrat James Martin, who narrowly defeated Bernard Taylor in the August 18 primary, 50.4% to 49.6%, now challenges Mast in the November 3 general election. Race ratings from Cook, Inside Elections, and Sabato classify the seat as solid or safe Republican, consistent with the district’s R+7 lean and Mast’s fundraising lead. Limited public polling since the primary leaves the precise margin buckets tightly clustered, while the low single-digit probability assigned to a Democratic win reflects residual contestation. Late-cycle factors such as turnout differentials, national midterm dynamics, or targeted endorsements could still shift the final spread before election day.