In 49 states (excepting Montana), the law is "employment-at-will", meaning that an employer can terminate you at any time for any reason, or no reason, unless otherwise proscribed. What this means is that you can be terminated for ANY reason unless the law protects your activity or class. For example Title VII (you cannot be terminated for your status in a protected class like race or sex), the ADA (disability), FMLA (medical leave), etc. Thus, most off-duty conduct is not protected although some states have laws protecting certain off-duty activities.

Can your employer terminate you because you were arrested for DUI, not on duty? Probably. Can your employer terminate you for dating a co-worker? Probably. Can your employer terminate you for attending a political rally? Probably. Can your employer terminate you for trying to form a union? No.

Florida has now legalized medical marijuana and there is an open question as to whether employers have any ability to regulate the use of marijuana while off-duty. What about states that have legalized recreational marijuana? What if this happens in Florida? Using the case below, what kind of activity do you think employers can proscribe in the case of medical marijuana? What about lawful recreational marijuana?

https://cases.justia.com/massachusetts/supreme-court/2017-sjc-12226.pdf?ts=1500300170