Well in all fairness I do personally know of several people with jobs in different areas of law enforcement that have (and still do) partake in very negative, but legal actions. These are actions that I consider to be even worse than smoking marijuana despite being legal, and I’m not necessarily confining these actions to alcohol use alone either.
To answer your question all I can say is that I’m not sure personally. If smoking weed should be an elimination factor for becoming a law enforcement officer than all crimes should be an elimination factor as well. My dad was a cop for 22 years before retiring from job related injuries and he would have answered no to your question.