can I sue my union for discrimination and retaliation?

i was a unionshop chairman and was removed from position for working in the office. i have been working in the office for 4 or 5 months. the union president sent a letter to the stewards stating that he was going to come to the company with banners to show the company that the members were ready to strike if conditions didn''t change. I told the president of the union that, thats not the climate in the shop and that no one is going to strike. when he came out with the banners and had little to no support from the members, i was told i was being removed from my position. he showed my in the by-laws that no one can be a steward and work in the office. but when a caucasian steward worked in the office and it was brought to his attention he took no action.