Marco Rubio leads the market at 29.5% due to his role as Secretary of State and acting national security adviser in the Trump administration, combined with donor and insider signals positioning him as a top choice for a potential 2028 running mate. Other contenders trail because the field remains fragmented pending clarity on the presidential nominee after the 2026 midterms. Greg Abbott benefits from his Texas governorship and border security focus, while figures such as Marjorie Taylor Greene, J.D. Vance, and Josh Hawley draw support from distinct ideological or regional bases. Key differentiators include Senate or executive experience, foreign policy credentials, fundraising networks, and alignment with administration priorities. Consolidation could occur through endorsements from Trump or the eventual nominee, strong midterm performance by aligned candidates, or shifts in polling that highlight electability in swing states.