Here are several examples of political bias/indoctrination/monocultures on college campuses:
- College faculty have overwhelmingly singular political preferences, based on their donations: https://www.thecollegefix.com/92-percent-of-college-faculty-...
- Professor who exposes lack of academic rigor in grievance studies is investigated by his university (Portland State) on "ethics" grounds: https://quillette.com/2019/07/29/when-ethics-review-becomes-...
- College students oppose free speech/thought/inquiry on campuses per polls: https://www.thecollegefix.com/shock-poll-most-students-oppos...
- University debate society bans Richard Dawkins from speaking to prioritize the "comfort" of their students: http://www.universitytimes.ie/2020/09/the-hist-will-not-be-m...
- University uses COVID as an excuse to ban some gatherings but not others based on ideology: https://www.scribd.com/document/477474467/Southeastern-Legal...
- University punishes student for his Instagram posts: https://reason.com/2020/07/24/fordham-university-disciplines...
- Professor threatens to fail students who write about Trump in a positive light: https://www.yaf.org/news/illinois-professor-threatens-to-fai...
- Professor bans student from class because he challenged the professor's views on gender: https://www.foxnews.com/us/college-student-kicked-out-of-cla...
- College tries to censor coursework that paints negative views of Islam: https://www.thefire.org/federal-court-rejects-unsound-lawsui...
I could keep going but this is what I was able to find quickly through search. The reality is that there is no room for views that go against the prevailing culture on most campuses today. Those who share the prevailing views are now in the camp of using the power of their supermajority to suppress/censor/punish/ban anyone who disagrees with them. Honest debate and truth seeking cannot take place in such an environment - and if that is true, then it follows that university environments tell people WHAT to think, not HOW to think, and that constitutes indoctrination.
You evidence demonstrates that is not the case -- many of those left-leaning professors are employed by institutions funded by the governments of red states.
Of course, it's completely reasonable for a sociology professor to think that social issues are important, just as much as we might expect a business or economics professor to believe that business or economics is important. And the things that people think are important influences a person's politics.
If you look at the academic disciplines that are interest groups that conservative politics align with, you'll find conservatives there: petroleum engineering, business, marketing, religious studies, etc. The thing is, there's just not that many academic focus areas that contemporary conservative politics prioritizes in their messaging.
In the end, I don't think the bias of individual professors at a university is a concern as much as institutional bias is. You can never really hire a professor who doesn't have an inherent interest in their own work. The important part is that we continue the western tradition of well-rounded study so that people are exposed to as many differing viewpoints as possible.
We probably both agree that individual bias cannot realistically be eliminated. However, I feel that despite biases, individuals shouldn't practice disingenuous academic behavior. As a quick example of this, I'll offer that sociologists regularly claim there is a significant gender pay gap without performing a multivariate study that controls for various confounding factors. If they exercised more rigor and held a sincere mentality of truth seeking, they would explore those obvious contradictions to their assumptions more readily, and also welcome the same explorations from their students and peers.
I think intolerance for different opinions is broader than just professors though. It's also campus administrators (https://www.nytimes.com/2018/10/16/opinion/liberal-college-a...) and the students themselves (https://www.thecollegefix.com/shock-poll-most-students-oppos...). If this intolerance persists or worsens, the outcome will be that anyone who disagrees must self-censor and express blind faith to avoid negative consequences. That's not academic freedom, but rather religious coercion.