The Republican Party appears to be divided between a tax-cutting old guard and a white-nationalist vanguard-and with Donald Trump's ascendance; the upstarts seem to be winning. Yet how are we to explain that; under Trump; the plutocrats have gotten almost everything they want; including a huge tax cut for corporations and the wealthy; regulation-killing executive actions; and a legion of business-friendly federal judges? Does the GOP represent forgotten Americans? Or does it represent the superrich? In Let Them Eat Tweets; best-selling political scientists Jacob S. Hacker and Paul Pierson offer a definitive answer: the Republican Party serves its plutocratic masters to a degree without precedent in modern global history. Conservative parties; by their nature; almost always side with the rich. But when faced with popular resistance; they usually make concessions; allowing some policies that benefit the working and middle classes. After all; how can a political party maintain power in a democracy if it serves only the interests of a narrow and wealthy slice of society? Today's Republicans have shown the way; doubling down on a truly radical; elite-benefiting economic agenda while at the same time making increasingly incendiary racial and cultural appeals to their almost entirely white base. Telling a forty-year story; Hacker and Pierson demonstrate that since the early 1980s; when inequality started spiking; extreme tax cutting; union busting; and deregulation have gone hand in hand with extreme race-baiting; outrage stoking; and disinformation. Instead of responding to the real challenges facing voters; the Republican Party offers division and distraction-most prominently; in the racist; nativist bile of the president's Twitter feed. As Hacker and Pierson argue; Trump isn't a break with the GOP's recent past. On the contrary; he embodies its tightening embrace of plutocracy and right-wing extremism-a dynamic Hacker and Pierson call plutocratic populism. As Trump and his far-right allies spew hatred and lies; Republicans in Congress and in statehouses attack social programs and funnel more and more money to the top 0.1 percent of Americans. Far from being at war with each other; reactionary plutocrats and right-wing populists have become the two faces of a party that now actively undermines democracy to achieve its goals against the will of the majority of Americans. Drawing on decades of research; Hacker and Pierson authoritatively explain the doom loop of tax cutting and fearmongering that characterizes our era-and reveal how we can fight back.