A "substate" governmental entity that engages in conduct that would usually violate the Sherman Act may escape liablity under the state-action doctrine if the "state" directs "substate" to do the anticompetitive deeds. But the state must "'clearly articulate[] and affirmatively express[]' state policy to displace competition." Fed'l Trade Comm'n v. Phoebe Putney Health Sys., Inc., No. 11-1160, slip