Six weeks ago, a teacher named Phil Mitchell reluctantly spoke to me about his unjust and forced exit from the history staff at the University of Colorado after 21 years in the classroom. All the evidence, notwithstanding the tortured spin of CU and its defenders, was that Mitchell, a reliable and well-regarded instructor, was being "let go" because of conservative political and evangelical Christian beliefs. Mitchell, who by the time I spoke with him was exploring job opportunities in more hospitable environs, decided to come forward with his complaints about the lack of diversity that hampered any true ideological debate....