With the Republican presidential field wide open for 2028 due to term limits, traders assign Marco Rubio the leading 29.5% implied probability for the vice-presidential nomination based on his Senate tenure, foreign policy record, and cross-faction appeal. Lower odds for contenders such as J.D. Vance, Greg Abbott, and Marjorie Taylor Greene reflect differing levels of national visibility, state-level executive experience, or alignment with key voting blocs. Differentiators among leaders center on legislative voting histories, regional strength in battleground states, and capacity to broaden the ticket’s electoral math. Support could consolidate through Senate confirmation patterns, midterm election outcomes, or early endorsements from party figures ahead of the primary calendar.