I would commend to you the research of Jeffrey Sachs, who's a political scientist at Acadia University. For years now, Dr. Sachs has been researching censorious reprisal and discipline against academic staff in North America.
Over the course of his research, he has found that in fact very few academic staff have been terminated because of their expression or their views, but overwhelmingly those who have been terminated have been on the left. It's very interesting, because there is a campaign by groups in the U.S. to characterize the left as censorious and as threatening the expression and scholarship of conservative scholars, but that's not borne out by the evidence when you look at the longitudinal analysis that Dr. Sachs has provided.