More on Tenure

OpinionJournal has an interesting piece on the fairly legitimate grievances of grad students pushing for unionization. Many of those problems, the article argues, stem from the tenure system. The irony of all those leftist university professors overseeing "the closest thing America has to serfdom" is certainly not lost on me.

In e-mail, someone brought up the difficulties of moving from a tenure system to any other system (like multi-year contracts with a good grievance system). Perhaps professors who already have tenure would simply have to be aged out of the system. Incoming and untenured professors would only be offered the new system. Tenured professors would have the option of moving to the new system, but if they chose to retain tenure, they would not have access to the grievance system and some other benefits. Some might choose the new system, some would stick with the old. Eventually, tenure would die.

Also, why don't professors have to retire at age 65 anymore? Is it government regulations or something else?