Thanks to a group of courageous and persistent students, George Mason University was recently forced to acknowledge that it had accepted millions of dollars from billionaire Charles Koch and other conservatives under arrangements that gave the donors input into several appointments at the university’s famously libertarian economics department. These arrangements violated traditional norms meant to insulate academic institutions from donor influence and come two years after similar gifts led to the naming of Mason’s law school after Supreme Court Justice Antonin Scalia.

The story fits neatly into the liberal narrative that the Koch brothers, Charles and David, have used their inherited oil wealth to fund the development of radical economic theories at Koch-funded universities. This, the narrative goes, translated into concrete policies at Koch-funded think tanks and legislation implemented by Koch-funded Republicans. For many liberals, this brainwashing of the American mind explains the ascent of the tea party and the election of Donald Trump.

There is some truth to this narrative of the rich, all-powerful puppeteers. But at Mason, the story is more complicated than that.

For the past seven years, I’ve been a professor at Mason. Although I teach economics and economic policy, I’m not a member of the economics department - they wouldn’t have me. But over the years, I’ve gotten to know and admire many of the economists there. For the most part, I have found them to be good economists and teachers, incredibly smart, intellectually honest and curious. In terms of the impact they have had on economics and the public debate on economic policy, they punch well above their weight class and have contributed significantly to Mason’s reputation as an up-and-coming public university.

Yes, the lavish support of Charles Koch and many other conservative donors has surely been a big factor in the department’s success and prominence. But any time someone makes a significant donation for a particular purpose, it influences a school’s priorities and identity.

When someone gives $10 million to an engineering school rather than the college of humanities, it changes the university’s priorities. When someone endows a center to study the causes and consequences of climate change, it affects who is hired and what is taught and researched. When someone gives enough to name a school after a public figure, it shapes a school’s ideological profile. It would be great if all donations were unrestricted, but they aren’t. Many donors have agendas; the Kochs are just an extreme example.

In the case of Mason’s economics department, the faculty have driven the donor relationships. In most instances, it was the faculty who approached and solicited Koch and other donors with specific projects in mind, not the other way around. Faculty also recruited and hired for the newly funded professors’ positions, decided which courses would be taught, chose which topics to research and selected the students who would attend its graduate programs. Our economics department is not libertarian and conservative because it is funded by Koch and his friends; they fund our economics department because its faculty is - and always has been - overwhelmingly conservative and libertarian.

If there is a problem here - and I think there is - it is that rules and norms of university governance give faculty the power to hire people who think like they do. This problem extends beyond the economics department and the law school - and well beyond Mason. There is ample evidence that feminists prefer to hire other feminists, behaviorists like to hire other behaviorists, “crit lit” scholars hire other “crit lit” scholars. Sorting by political or academic ideology is a naturally occurring phenomenon at universities.

This lack of ideological diversity is bad for students. It hurts them if good candidates don’t apply for faculty positions, or if other students do not apply for admission because they presume they would not be selected or fit in. And it hurts students if the professors believe they are free to impose their political or academic ideology on their students.

The challenge is figuring out what to do about it. One can imagine the faculty outrage if a provost were to tell a department that it had to use its next two hires to achieve greater ideological diversity. And any dean who told a professor that she should revise her lectures to expose students to a wider range of viewpoints would almost surely be censured for violating academic freedom.

Yet such actions, I would argue, are sometimes necessary. It would have been better if Mason’s presidents and provosts had insisted on more ideological diversity in the law school and the economics department, as well as in the few units where a similar liberal orthodoxy prevails. The reason they didn’t, however, probably has less to do with the undue influence of donors than with faculty who jealously guard their prerogatives to hire whomever they want to hire, teach whatever they want to teach and solicit funding from wherever they can get it.