That’s an interesting concern; thanks for raising it Michael. I think the best way to think through it is to imagine the alternative universe without tenure. In that world, where professors like me would be on some 2–3 year reappointment schedule, or could be fired for any legal reason, wouldn’t we have even less incentive to speak our mind, for fear of dismissal? In fact, it’s easy to compare my role to my colleagues who are in non-tenured teaching track positions. They regular censor themselves or ask me to advocate something because they know their position is on contract. They know I can take risks in public without risking my job. They’re not so sure what the consequences would be for them.
None if this is to say that tenure actively promotes professors’ involvement in public life, but it certainly enables it. I think many universities, especially public ones, should consider changing their tenure and promotion requirements to include public engagement explicitly. That would create an incentive that leverages the promise of tenure, while giving people practice at being public.