Universities and colleges are supposed be places where bright students expand their worlds, question old ideas, test new ones, think, write about their thinking, meet and learn from people with different ideas than their own. These people are usually liberals: they vote Democratic. People who see themselves surrounded by strange illogical socio-political conspiracies, yearn for good old days that never really were, think governments are systematically and secretly poisoning citizens are conservatives and do not go to universities or colleges seeking new experiences and new knowledge.
So yes, colleges and universities have a greater % of Democrats than the average city or town but they are not anti-conservative. Many professors are Republicans. Conservative subjects and ideas are taught in classes as are liberal subjects and ideas. Political science departments teach Marxism alongside of other isms. Republican speakers are on campus almost as often as Democratic. People like George Will, Mary Matalin, Charles Krauthammer (God rest his soul) Thomas Sowell, Peggy Noonan, the Pauls, Newt Gingrich are conservative speakers welcome on all campuses to give talks and seminars with many attendees. When they were alive William Buckley, Antonine Scalia, Barry Goldwater, Billy Kristol and many other conservatives had full schedules speaking at universities.
People like Milo Yiannopoulos, Ann Coulter, Matt Drudge, Jennifer Geller, Donald Trump, Rush Limbaugh and Howie Carr have indeed not been welcome on campus. They are not speakers. They have no ideas they want to expound on. They have nothing to teach. They are not conservatives in the traditional political sense. They are provocateurs, throwing verbal bombs, starting riots, causing hate and walking away while people are left to clean up after their mess. They scream loudly about freedom of speech and idiots listen to them.