These federal benefits should only be available to those who earnestly want to get back on their feet — people who abuse illegal drugs have clearly not made that commitment. This drug testing program would weed out the people who should not be collecting benefits funded by taxpayer dollars.
Illegal drug use is not higher among the welfare beneficiary population than it is in the general population — legislation like this aims to target the needy, creating stigmas about the poor, and whether they "really need" benefits. There are also questions about the constitutionality of these tests.