I believe that the best solution would be a massive unionization of nontenurable faculty; since, unlike tenure-track faculty, non-tenured faculty can be unionized at private and public universities, the most effective way to protect teachers and teaching at American universities is to gain job security and due process through enforceable contracts.
What I do think will happen, then, is that the number of faculty with tenure will continue to decrease but not disappear, while the number of non-tenured faculty protected through unionization will increase. This situation will replicate what we already have at the University of California, where the non-tenure-track lecturers are unionized, but the tenured professors are not. If my hypothesis is correct, we will see the UC model spread across the country, and this will set in place, nationally, the types of battles we are currently seeing in California.
One of the interesting things that I have discovered in the last few years is that since the non-tenure-track lecturers now do a large portion of the undergraduate instruction in the UC system, and our jobs are defined as teaching-centered, we have been able to form a strong coalition with students and parents to protect undergraduate education. Furthermore, because we have a contract that has to be respected by the administration, we have sometimes been able to counter many bad administrative decisions in a more effective way than the tenured professors. For instance, we have fought against the rapid increase of class sizes, and we have also resisted the move to online courses and the elimination of requirements. While we have often partnered with tenured faculty members, we have been surprised to discover that professors have lost much of their say in shared governance.
Didn’t some other brilliant guy I know, just say that?
* I, of course, would rather do both.