I'm under the impression that in Pennsylvania, medical marijuana users are protected from employer discrimination:
No employer may discharge, threaten, refuse to hire or otherwise discriminate or retaliate against an employee regarding an employee's compensation, terms, conditions, location or privileges solely on the basis of such employee's status as an individual who is certified to use medical marijuana.
Section 2103(b)(1), Pennsylvania Medical Marijuana Act, 2016.
How does this work in practice? Particularly, does it protect "green card" holders from a positive drug test during the hiring process? Is it correct that withdrawing a job offer based on a test positive for THC products would be illegal by this legislation? If so, to what extent do employers feel bound by this act (currently, in Pennsylvania); i.e. whether in knowing or unknowing defiance of this act, would a company be likely to feel comfortable withdrawing a job offer after a positive test?