(AP Photo/Evan Vucci) Trump speaks at Miramar Air Corps Station in San Diego on March 13, 2018. D on’t get me wrong—Donald J. Trump is a noxious gasbag, a flouter of the Constitution, and president of the United States. But he’s not the problem; he’s the symptom. Before Cambridge Analytica was plying its “psychographic” wizardry on Trump’s behalf, it did so for Ted Cruz , the U.S. senator from Texas and would-be U.S. president, and Ken Cuccinelli , the would-be governor of Virginia. Before Trump spoke of “my African American there” at a rally or tweeted out false statistics about black crime, Representative Joe Wilson of South Carolina shouted “You lie!” at a sitting U.S. president as he addressed a joint session of Congress. That president, of course, was Barack Obama, the nation’s first black commander-in-chief. You might recall that the source of Wilson’s ire was the prospect of free health care that he said Obama would deliver to undocumented immigrants, despite the president’s...