If your employer is a state of local government agency, your situation may present a constitutional issue. A quasi-governmental function would present an interesting wrinkle. If your employer is a private company or person, there are certain Michigan statutes protecting workers that might help you. More details would be helpful, such as whether you work under a collective bargaining agreement or a formal contract or employer's manual of work rules. For some home care workers, there has been...
A new federal law makes it more difficult to obtain habeas corpus relief, however, it can still be done in most cases in my experience. I think what you are after is to challenge your conviction and fully rehabilitate your civil rights. Each case is different, but there are often other ways to do this. You should discuss this with an attorney. Thomas Rasmusson 517-324-1117
It was not clear from your question which court is involved. Most of the local courts use a testing method that the federal government and experts say is unreliable. You did not mention whether you had been drinking. If you had not been drinking, yours may be one of those false positives. I concur in the advice of the other responses of local counsel. Thomas Rasmusson
Your sense of the thing is correct. The employer is bound, if there is an express contract or, as here, you were given a reasonable expectation of employment. There are over twenty (20) recent cases in Michigan on this point. I would want to go over details, to be sure. Thomas Rasmusson 517-324-1117