Trader consensus on Polymarket places Marco Rubio at 24.5% as the leading Republican VP nominee for 2028, driven by his high-profile performance as Secretary of State, including recent diplomatic successes that have impressed donors and boosted his national stature amid speculation on post-Trump tickets. Mike Pence at 20.3% and Vivek Ramaswamy at 20.0% reflect trader bets on establishment conservatives and rising MAGA voices to balance potential presidential frontrunners like J.D. Vance, whose current VP role has not solidified VP odds above 11%. The tight clustering stems from uncertainty over the 2028 GOP presidential primary, with no dominant nominee yet emerging; separation could arise from 2026 midterm results elevating governors like Kristi Noem, key endorsements, or shifts in Trump family influence on the party.