The Romney-Gingrich rivalry is set to intensify ahead of the Florida vote with a new infusion of cash from outside backers. On Monday, it was revealed Gingrich supporter Miriam Adelson will donate $5 million to the pro-Gingrich super PAC “Winning Our Future,” which has run a series of ads attacking Romney. Adelson’s husband, the casino magnate Sheldon Adelson, recently gave Winning Our Future another $5 million.