I have a question for Colorado. Perhaps they have answered it; I have not read through the legislation related to the legalization of marijuana. Given that recreational use of the substance is now legal, does that mean that it is now illegal for employers to test for it, or to fire someone for using it?
I ask because I can think of quite a few jobs for which I would want the person performing them to be sober in every sense of the word. Many manufacturing jobs are dangerous, with serious employee injuries even when everyone is attentive--and the injury does not always fall upon, or soley upon, the inattentive worker. I would not want to work on an assembly line with someone who was functionally impaired, and in most places I do not have to--the plant managers are eager to prevent worker injuries, and will remove someone from the building who is obviously intoxicated. There are other dangers in other jobs, though. I would not want those responsible for handling the books in the bank to be compromised, nor the mechanics who maintain my vehicle. Even fast food restaurant jobs can be unsafe for someone whose faculties are infacilitated. For nearly any job you can identify, a sober worker is a safer worker--not to mention a better one.
From many jobs, you can be terminated if you come to work noticeably intoxicated, sometimes with sometimes without a warning system or a rehabilitation option. The problem with drugs, though, is that they are not as easy to recognize--someone can be just as dangerous on some drug other than alcohol, but not be recognizably so. Drug testing, in its present state, generally can identify whether someone has used a drug "recently", but not whether he is under the influence at this moment. Can an employer dictate that his employees must pass drug tests that prove that they are not using legal non-prescription drugs when they are not at work, as a safety and efficiency requirement? Or would that be illegal?
Of course, that does not apply in those states in which marijuana is still illegal; but if other states are considering whether to legalize it, these are the kinds of questions that need to be addressed. Can your employer fire you for engaging in a perfectly legal recreational activity? How much of a rational basis connection does there have to be to job safety and performance? How do we reach those answers?