Teresa A. Sullivan, president of the University of Virginia, talked about how her institution had handled — and mishandled — the white-supremacist rallies in Charlottesville last year. “We thought we were doing a good job of monitoring social media, but we weren’t,” Sullivan said during the opening plenary, on Sunday. But once she got wind that the racist protesters were planning to march on the campus, she got her general counsel involved right away. Campus lawyers, she said, play a crucial role when there’s unrest.