College campus should have active debates with open sources of information.  But when special interest group want to bring a declared racist onto campus, it's hardly their intent is to have an open and honest discussion.     These are people brought to persuade, not to have an intellectual discussion.  I have zero problem with the crowd becoming the dissent to the lecturers opinion if one isn't formally presented.

A topic should have advocates for all sides of an issue (there is seldom only TWO).    A little creative design by school administrators should be able to do this.