Trader consensus prices the chance that Marco Rubio overtakes or displaces JD Vance as the leading 2028 GOP presidential contender by October 31 at just 2 percent. Rubio has repeatedly stated he has no plans to run if Vance seeks the nomination and would support him, while Vance maintains a substantial lead in national primary polling averages and prediction markets as the vice president and early frontrunner. Recent straw polls show Rubio performing strongly in some conservative gatherings, yet these have not altered the broader positioning or prompted any public shift from either figure. With the resolution window only weeks away and no scheduled events or announcements expected to produce a rapid realignment, traders see little scope for the required reversal before the deadline.