The latest upsurge in American populism continues to make waves. In this useful and balanced book, two well-known pollsters, one (Rasmussen) associated with the GOP and the other (Schoen) known for his work with Democrats, try to come to grips with the intensity and implications of Americans’ growing disenchantment with their political and intellectual leadership. The book looks at both the left- and the right-wing populism in the United States today. The Tea Party movement may be the latest and most dramatic illustration of voter discontent, but Schoen and Rasmussen remind us of the left-leaning populism that was a driving force in American politics during the waning years of the George W. Bush administration. While the populism of the right is clearly more energetic this political season, the left’s populism is a force that no Democrat can ignore. One of Schoen and Rasmussen’s most useful approaches is to try to measure the gap between what they call “mainstream Americans” and “the political class.” The reader learns, for example, that in April 2009, 19 percent of the political class believed that “tax increases hurt the economy,” while 74 percent of mainstream Americans accepted that idea. Sixty-one percent of the political class believed that the financial bailouts were a good idea; 59 percent of the mainstream thought they were bad. Rasmussen and Schoen argue that the populist anger is more than a passing phenomenon; they believe that a significant wave of historic political change is taking shape. Readers who think they are in the political class might do well to pay heed.