You can look at it this way: In the United States, the more education you have, the more likely you are to be some kind of “liberal.” You are also more likely to be some kind of conservative the more educated you are, up through people with college degrees, but people with graduate or professional degrees are the least likely to identify as conservatives. http://www.people-press.org/2016/04/26/a-wider-ideological-gap-between-more-and-less-educated-adults/4-22-2016_01/
Guess what? The vast majority of University of Chicago undergraduates will eventually be people with a graduate or professional degree. That’s who they are. I think the University of Chicago is more open to conservatives than most comparable institutions, and there is more respect for conservative ideas, but there’s no question that the students and faculty skew left, as they do at every elite university.