To limit the spread of disease, State A provides drug addicts with clean needles at taxpayer expense with which to inject drugs. State B$$s taxpayers cannot tolerate encouraging illicit drug use and refuse to provide clean needles at taxpayer expense, not realizing that these same taxpayers pay on the back end, when these drug users visit the emergency room without the ability to pay. These difference in needle policy typify U$.$S$.$ Supreme Court justice Louis Brandeis$$s characterization of states as $\_\_\_\_\_\_.$