My freshman year of college, the first left wing college teacher that I encountered was in English 101. She had posted an A as my mid term grade. Then, a class paper on the upcoming Presidential election, in which I naively advocated for the Republican candidate, resulted in a grade of F. Even worse, when she returned the paper during class, she verbally attacked me for my opinion. I eked out a C in the course. In subsequent semesters of English, I earned an A and two B's.
BTW, that happened in the Fall of 1952, the candidates were Eisenhower and Stevenson. Nothing new about liberal bias in Academe.