A new poll by NBC News and the Wall Street Journal reveals that public perceptions about race relations in America have taken a devastating hit since the election of Barack Obama. At the beginning of the president’s first term, 79 percent of whites and 63 percent of blacks had a positive view of American race relations. Those numbers have plummeted to 52 percent and 38 percent, respectively. Meanwhile, 45 percent of whites now consider race relations fairly or very bad, compared with 20 percent in 2009, and the negative views held by black Americans has jumped from 30 percent to...