At the risk of being flamed here just how is an employer has the right to make what seems to be a warrant-less search of someones body? And prior to drug screening, how did people manage to find jobs employers needed filled? I’d agree certain occupations require a clear head but this to me is just Big Brother. If it’s drug screening you want then every member of the House and Senate and POTUS should be tested too.
The test is given only with the consent of the testee. If you don't want to take the test, then don't. If I don't want to employ you because of the refusal, I won't. Each party has a choice, more powerful for each in right-to-work states.