Cary Nelson makes a case for tenure (for college professors) in The Chronicle of Higher Education. An excerpt:
Tenure serves your personal interest and the national interest at the same time. Your tuition dollars are an investment. If you want to increase the chances that your investment will pay off, if you want to get the best value for your money, then make certain that the college your family chooses grants tenure to its professors. The gradual erosion of tenure has meant that thousands of faculty members are vulnerable to administrative, political, or religious pique and whim. Attacks in the press may make things still worse.