Why are so many people now embracing demagogues? Barbara Walter, political scientist and author of “How Civil Wars Start,” says that the vital signs of healthy democracy are in decline around the world.

ProPublica Deputy Managing Editor Eric Umansky’s family saw an unmarked NYPD cruiser hit a Black teenager. He tried to find out how it happened, and instead found all of the ways the NYPD is shielded from accountability.