Crosby v. National Foreign Trade Council

Massachusetts (defendant) enacted a law barring the state from purchasing goods or services from companies doing business with Burma, around the same time Congress separately authorized the President to impose and waive economic sanctions against Burma based on national-security and foreign-policy considerations; the National Foreign Trade Council (plaintiff), representing companies on Massachusetts's restricted list, sued, and the lower courts ruled the state law unconstitutionally interfered with federal foreign-affairs power.