In 1960, when JFK defeated Nixon, America was a nation of 160 million, 90 percent white and 10 percent black, with a few million Hispanics and Asians sprinkled among us. We were one nation, one people. We worshipped the same God, spoke the same English language, studied American history and English literature, honored the same heroes, read the same books, watched the same TV shows, went to the same movies and saw ourselves as defenders of Western civilization against the godless communism of the Soviet Empire. We were confident and proud of who we were. That was yesterday. But due...