JD Vance holds the highest implied probability at 22% in the 2028 presidential winner market, reflecting his position as sitting vice president and consistent leads in early Republican primary polling around 38%. The Democratic side shows greater fragmentation, with Alexandria Ocasio-Cortez at 13% and Jon Ossoff at 10% ahead of polling leader Kamala Harris at 4.5%, as traders weigh name recognition, potential Senate bids, and post-2026 midterm dynamics against established survey results. No major candidates have declared, leaving room for shifts from primary contests, endorsements, or late entrants. The broad field and divergence between polls and market pricing underscore uncertainty more than two years out.