Conservative politicians, including Mitt Romney during his presidential campaign, supported legislation mandating drug testing for recipients of federal aid, such as: the unemployed, families in assistance programs -- in general, citizens down on their luck or in trouble. Interestingly, none of these politicians has suggested drug tests for executives whose banks benefit from billions in federal aid and bailouts.
Since 2011 (generally, at Republican insistence):
"Seven states have passed laws mandating drug tests for [welfare] recipients, and in 2012 at least twenty-five other states considered proposals to tie welfare cash assistance, and in some cases also food stamps, to drug tests." (Source: The Nation)
For example, in 2011, GOP Governor Scott of Florida signed a law requiring all applicants for that state's welfare program to take a drug test. And in 2012: