The Dispatch: “Marco Rubio is vowing not to challenge Vice President J.D. Vance for the Republican nomination, a decision that appears to preclude the secretary of state from launching a 2028 White House bid.”“But many GOP insiders believe that commitment is less ironclad than it seems…”“Also sparking speculation that Rubio is keeping his options open is the existence of a political nonprofit group founded and run by close political advisers.”