Ban THC/Marijuana drug screening for employment

Marijuana is now legal in most states (should be all) but theres absolutely no reason an employer should be able to tell me i cant participate in a LEGAL activity when i am off the clock.
Marijuana effects go away much faster than the effects of alcohol but theres no pre employment test for alcoholics.
I would rather work next to someone that smoked a joint last night than work next to the guy that is hungover.

drug testing for them