I was asking about his race, and if that was a factor, as it could be a basis to sue.
Lets back up...
AL is an "at will" state...In an "at will" employer/employee relationship, either side can end OR modify the relationship (the employer can fire the employee or demote them or the employee can quit) "at will".
As an "at will" employee your son's options are limited. His employer can demote for a good reason, or no reason at all. The only thing that they can not do is demote for a "bad" reason. A "bad" reason would be if they demoted him based on race, ethnicity, national origin, religion or gender some other protected class (like if you were a "whistleblower")
So they can demote.
This is the part of my job I don't like...when the law is not in favor of my customer. I wish I could tell you that they can not demote, but I can only provide you information based on the law so that you can act on the best available information to you...I wish I had better news, but can only hope you recognize and understand my predicament and don't shoot the messenger. I'm sorry!
Please let me know if you have more questions. I am happy to help if I can. Otherwise, please rate the answer so I may get credit for my work.