Substance abuse has been a concern and issue since the 1996 federal welfare reform.
Gathering more information on the idea that welfare applicants or any applicant that is in need of public assistance should undergo a drug test I wanted to know if there are any states that are already doing this.

12 states that approved this legislation:

1. Alabama (2014) "Drug testing with suspicion"
2. Arizona (2011) "Drug testing with suspicion"
3. Florida (2011) "Drug testing ALL participants"
4. Georgia (2012) "Drug testing ALL participants"
5. Kansas (2013) "Drug testing with suspicion"
6. Michigan (2014) "Drug testing with suspicion"
7. Mississippi (2014) "Drug testing with suspicion"
8. Missouri (2011) "Drug testing with suspicion"
9. North Carolina (2013) "Drug testing with suspicion"
10. Oklahoma (2012) "Drug testing ALL participants"
11. Tennessee (2012) "Drug testing with suspicion"
12. Utah (2012) "Drug testing with suspicion"

Not all states are drugs testing ALL welfare participants or recipients some have specific exceptions where a participant or recipient will only be drug tested if he or she is believed to be using drugs. This exception is because when this legislation was first proposed one of the arguments against this was that it was "unconstitutional" to do suspicionless or random drug testing. This goes against the 4th amendment where participants shouldn't be drug tested with out having reasons to believe they are abusing drugs.
This makes complete sense to me because in a way it is assuming that welfare participants are driven into drugs , why? because they are poor perhaps? Many can argue that the low income families are doing nothing but trying to better their lives and drugs are not a part of that mission.
There is no evidence that the poor use more drugs than any other socio economic group....

http://www.ncsl.org/research/human-services/drug-testing-and-public-assistance.aspx