In the news there is currently much discussion about whether universities can say "no" to individuals who might speak on campus. Primarily conservative speakers have had their speaking "gigs" cancelled primarily because the "messages" of these speakers may generate undesired responses.
I am hoping that these university boards/trustees are not making a case-by-case decision about speakers. These decisions would be "ists" and difficult to defend based on most standards (other than "we just don't like them based on what they have to say"). Instead, responsible boards will have taken the time to identify their core principles to ensure their decisions on these matters are consistent with institutional values and mission.
The role of the board as policy maker is core to its fiduciary and strategic role as surrogate owners of a nonprofit institution. Effective policies are fully informed, value and mission driven guidelines/rules that inform day-to-day decisions. Conversely, policies made on-the-fly or for unique situations and uninformed by values and mission often result in institutional chaos and conflict, internally and externally. For efficiency and effectiveness sake, nonprofit boards should value the former, not the latter.