RFK Jr. leads the 2028 Republican presidential nominee market at 49 percent according to current trader consensus, ahead of J.D. Vance at 30.8 percent and Marco Rubio at 18.8 percent. This positioning reflects post-2024 election realignments within the party, including shifts in candidate visibility and alignment with key voter coalitions. Vance and Rubio draw support from their administration roles and Senate records, while lower-probability options such as Ron DeSantis at 16.4 percent and Brian Kemp at 4.5 percent track state-level records and prior primary showings. The wide distribution across more than thirty names indicates an open field more than two years from the first primaries, with odds sensitive to future announcements, legislative votes, and polling trends in early states.