Do I have a case?

I was recently demoted from shop lead to a standard worker without any explanation in front of two of my workers that I had been the lead for. The Manager called all three of us into his office and told me "I am making some changes, I'm pulling your shirt (lead position) effective immediately. I have already sent the memo. You have had enough chances (not sure what he meant as I had no reprimands prior). With that being said, you are excused, have a nice weekend." Again this was humiliating for me as it was in front of two members of my crew. This happend on Friday 2/25/2011 at 2:45pm and we secure at 3:00pm. This has devasted me as I have never been treated with such little respect in my life, especially from a retired Navy Chief. I have been a lead for just over two years, and been employed at this base since 1996, with a 3 year absence from 12/2005 to 1/2009. This manager has only been with the company for less than six months. My work record speaks for itself. It is not losing the position that has caused my anguish but the humiliating manner in which I was treated.