GAINESVILLE, Fla. - There was standing room only for the volunteers gathered near the University of Florida on a recent afternoon to learn how they could campaign in favor of a referendum to enshrine abortion rights in the state constitution. Among the tips they got: Don’t mention President Biden or Donald Trump by name. Describe abortion as a health-care issue, not a political one. And don’t be afraid to get personal.Subscribe to The Post Most newsletter for the most important and interesting s