I get e-mails all the time from people that have been fired for failing a drug test for marijuana, asking what they can do to get their jobs back. People think that because they live in a state where medical marijuana and/or recreational marijuana is legal, that they can't be fired for failing a drug test for marijuana. This scenario is currently playing out in New Mexico, where a woman is suing her former employer for firing her for failing a drug test. Per Businessweek:
A woman in New Mexico is suing a company she says fired her for failing a drug test, even though she had a state-issued medical marijuana card. The ex-employee, Donna Smith, says Presbyterian Health Services' decision to terminate her violates the New Mexico Human Rights Act, which prohibits discrimination against people with serious medical conditions.
Smith's attorney, Jason Flores-Williams, argues it's "absolute hypocrisy" to punish employees for outside-work use of doctor-advised marijuana, but not alcohol, Adderall, or antidepressants. Smith, a physician's assistant, was diagnosed with post-traumatic stress disorder in 1997 after serving in the military.
Multiple people have tried to win lawsuits and/or get their jobs back after being fired for marijuana consumption. Unfortunately, all of them have lost in court. They usually lose because they are relying on state law, which is superseded by federal law when it comes to employment. Federal law didn't always trump state employment laws, but due to patronage reforms in the late 1800's/early 1900's, and discrimination reform in the mid/late 1900's, there is quite a bit of case law that rules in favor of the federal government. I'm not confident that this case will be won, however, as I always say, just because the firing was technically legal, it doesn't make it moral. No one should be fired for marijuana when zero impairment at work has ever been proven.