Get your grade and move on. If you really feel like you need to say something, do it after you have your grade/graduated. This might sound like you are backing down from a fight but there are times to voice your opinions and be heard and times fly under the radar. People like that will have no moral objection to sinking you and he will win. Beat him to the punch by getting your A and moving on with life. If it makes you feel better, right a paper on why you think he is an assclown and wrong. Then sit on it until you have graduated. If you still feel like you should tell him where he can shove his opinions, then mail it to him.
Good luck!