Judges can too. In fact, even in my very limited experience, I can think of only two judges I've met that I'd consider "fair". Judges get elected and promoted as politically as prosecutors do, and, like prosecutors, benefit more from a "tough on crime" platform than they do on a "fair to guilty people" platform.

My favorite memory of this is the time that a judge and the public defender were openly mocking a defendant in the court room.