In the Chronicle of Higher Education, a former president of Harvard, Derek Bok, weighs in:
A problem that is especially difficult to correct is the predominance of liberal and liberal-leaning professors, especially in social-science and humanities departments, where they often outnumber conservatives by 10 or even 15 to one. As a result, there is an important body of conservative thought that is now nearly or completely absent on the faculties of many eminent universities. That is not ideal for educating students or for fruitful collegial discussion and disagreement within the faculty. Surveys show that most professors in most universities agree.
In seeking to solve this problem, universities should certainly not compromise their rigorous standards for making faculty appointments. Still, it is possible to make some immediate progress by trying to hire conservatives as visiting professors or lecturers while also encouraging conservative students with ability to consider embarking on an academic career.
Universities with predominantly liberal faculties also need to take particular care not to indoctrinate their students or appear to be doing so.
That makes some sense. I did find Bok's explanation of the imbalance to be somewhat problematic: "university faculties, especially at elite institutions, became more and more liberal in their political orientation. Careful studies have found that this tendency has not come about primarily through conscious discrimination in hiring professors but is chiefly a result of liberals' being more attracted than conservatives to academic careers. This tendency seems to begin even before students reach college and is enhanced by the distaste of many highly educated people for a political party that opposes abortion, gun control, and efforts to cope with climate change."
The "careful studies" aren't cited or hyperlinked. Perhaps conservatives have a distaste for campuses where opposition to abortion, support for Second Amendment rights, and skepticism of overwrought climate-change-panic are assumed to be indicators of insufficient education.
When Bok was president of Harvard he did a pretty good job of having conservatives or moderate liberals on the faculty, including some of my favorite professors.