I have never had this problem!?

I have been an acting supervisor for almost 2 yrs. I can handle all aspects of the job. Recently, they hired a man who is a retired chief in the navy and then after 3 months of training promoted him over me and he is now my leadman. He does not like me and feels threatened by me. I was told to train him and he says he doesn't need training. WRONG! He dogs every thing I do and doents how long it takes me to finish projects even though the other 3 guys in my office are not productive workers. Last week he YELLED at me two different days in the office in front of people. Today I gave up the acting supervisor position (.40 more and hr) and now I can just be a clerk. I am the only girl in the office and he is the only black man. I was told he is trying to get me fired so he can be the big man. What should I do? He said I am slandering him when I don't agree with what he says. I think he is haring me. Today he called in my in my union rep and asked how to get me. (paraphrase)