**Vance leads early 2028 Republican nomination polling and prediction markets at roughly 48 percent, ahead of Rubio near 15 percent, yet Trump has issued no public endorsement and has repeatedly described the timing as premature.** This keeps the first-endorsement market closely balanced, with traders assigning a slight edge to “No” at 54.5 percent. Key variables include the November 2026 midterms, which may reshape party dynamics before serious positioning begins; Trump’s past pattern of influential but not always decisive primary backing; and the possibility that an early favorite encounters headwinds from a broad field of cabinet officials, senators, and governors. Late shifts in polling, candidate declarations, or an unexpected endorsement recipient could quickly alter the implied probabilities.