PBS News Hour: April 21, 2016

Overview

Thursday on the NewsHour, controversies over rules dominate the day on the campaign trail. Also: Inside the electoral battles for Pennsylvania and Maryland, how trade policy is playing out in the race for the White House, why the U.S.-Saudi relationship is under strain, the fight over a carbon tax in Washington state, the co-founder of AOL offers his vision of the future and looking back on Prince at his best.