Republican megadonor Ken Griffin said at a private conference Wednesday that he'd support Secretary of State Marco Rubio over Vice President JD Vance in a 2028 GOP presidential primary, Axios has learned. Why it matters: Griffin is one of the most prolific donors in the Republican Party — he gave more than $100 million in 2024 — and would be a huge asset to Rubio if the secretary of state were to run for president. Griffin's comments reflected the emerging split in the GOP between establishment