What do you get when you mix strong partisanship, weak parties, and an increasingly powerful executive branch? Nothing good, argue Nicholas Jacobs and Sidney Milkis in What Happened to the Vital Center? Presidentialism, Populist Revolt, and the Fracturing of America. In this book, the authors examine the increasingly fraught interactions among populist movements, party politics, and presidentialism.

In my view, the book is motivated by a question that most, if not all of us, have asked ourselves over the past several years: What happened to our political system that allowed Donald Trump to become president? Trump won the Republican nomination, despite no history of participating in Republican politics or even being a Republican. In fact, he was initially opposed by most of the party elite. Yet, he captured the nomination anyway, an event that would have been unthinkable in previous eras. The fact that the party apparatus was unable to stop this hostile takeover was compounded by the fact that Republican voters did not seem to care. Trump won the 2016 presidential election with overwhelming support from Republican partisans.

As Jacobs and Milkis note, populist movements are nothing new. Chapter 2 provides a historical overview of many of the country’s seemingly cyclical populist movements, including the anti-Masonry movement in the 1820s, the agrarian populism of William Jennings Bryan, and Father Coughlin and the America First movement in the 1930s. What separates our current populist movement from these earlier iterations of the phenomenon, the authors argue, is the party system’s inability to contain it. Most previous populist movements fared poorly in the face of strong party organizations. For this reason, populist anger generally failed to gain traction within the parties themselves. Across history, Jacobs and Milkis argue, party organizations blunted the impact of populist movements and their ability to translate the populist zeitgeist into substantive representation in government.

Yet, as evidenced by Trump’s ability to ride a populist wave into the White House, the party organizations today seem far less capable of offering effective resistance. The authors attribute this inability to a pair of linked forces: the increasing importance of the presidency post–New Deal and the concomitant weakening of the party organizations. The expansion of the administrative state, starting with the New Deal and continuing throughout the twentieth century, made the presidency more important. The growth of the federal government created a new pathway for the president to reshape policy through unilateral control of the bureaucracy.

As a result, American politics are increasingly president centric. State and local party organizations have been hollowed out as the fortunes of state and local candidates now rise and fall along with the presidential candidates. These changes, along with changes in campaign finance, media environment, and the McGovern-Fraser institutional reforms of the early 1970s, which were purported to make party nominations more democratic and transparent, have worked to make parties as organizations less powerful and less relevant (p. 173).

Strong parties have been replaced by strong, executive-centered partisanship. This allows presidential aspirants to form their own personal coalitions and raise money while not being beholden to a party apparatus and, perhaps more concerning, even to the party system itself (p. 30). The flip side of this equation is that party organizations have fewer and fewer tools at their disposal to control candidate selection. This lack of institutional control opens the door for candidates, populist or otherwise. who may have once been stopped by the party machinery, to gain access to the ballot and therefore power. For Jacobs and Milkis, party organizations—once the mechanism that kept the dangers of populism at bay—no longer provide effective guardrails.

The strength of this book lies in the authors’ ability to connect deep structural changes to institutions—particularly the presidency—that unfolded over the course of decades to shape the current tumultuous and, in my estimation, scary state of American politics. Our politics has indeed become president centric, and this book explains both why this has occurred and the fundamentally problematical consequences that follow from this shift.

One of the great limitations with contemporary quantitative political science is that public opinion data do not go back very far in time. We tend to assume that American politics began when the American National Election Study (ANES) started to survey voters. The American political development approach is a welcome corrective here. Scholars of all stripes need to take the historical and political context into account. Politics look like they do today, as the authors note, because the nature of the administrative state, and therefore the presidency, began its dramatic shift in the 1930s in response to the Great Depression. Now, nearly a century later, presidents from both the Right and Left use the great power of the presidency to unilaterally bend the entire administrative state toward their preferred policy goals.

Although I think this book fundamentally diagnoses the political story and the contemporary problems facing our experiment in self-government correctly, it left me with some questions about the “vital center” from which the book gets it title. The term, borrowed from a book by Arthur Schlesinger Jr. of the same name, is a broad one. It refers to the shared belief in liberal values and fundamental democratic principles that both parties endorsed in the wake of World War II. The authors argue that the vital center has broken down and that America would be well served if this consensus was reforged.

My biggest question on this score is the degree to which this “vital center” rested historically on a foundation of African American exclusion. As the authors note, the vital center has failed before, with the Civil War being the most glaring example. My read of the evidence is that periods of elite consensus coincide with efforts to keep African American civil rights off the national agenda. The vital center can reduce polarization by colluding to keep polarizing issues off the national agenda, and in American society, there is no issue more enduringly polarizing than what rights Black people should have. Politics gets tumultuous and sometimes violent when civil rights issues come to the forefront. There is a fundamental tension between stability and multiracial democracy, and often the elite consensus has come down on the side of the former at the expense of the latter.

As the authors point out, the postwar consensus broke down when civil rights activists forced the issue onto the national agenda in the early 1960s. One hundred years earlier, the Civil War ripped the country apart, and Reconstruction produced a Southern White insurgency against the federal government that lasted until 1877, when Republicans and Democrats cut a deal to settle the disputed 1876 presidential election by granting Republican Rutherford Hayes the Electoral Votes from four contested states (and therefore the presidency) in exchange for ending Southern Reconstruction. Here, the partisan elites colluded to exclude Blacks from the political process, and this status quo lasted for nearly 100 years. This decision might have made elite politics more consensual, but it came at the expense of African Americans. When the debate over multiracial democracy reemerged in the national consciousness in the 1960s, elite consensus began to falter, and stability gave way to massive social change and the associated instability. We now have a system that is more democratic but perhaps less stable. Is a vital center possible when African American civil rights are allowed to come to the political forefront? To me, this is an open question that links the rise of a figure like Trump in the aftermath of the collapse of the racially exclusionary “vital center” very tightly to issues of racism and white identity politics.

Overall, Jacobs and Milkis’s thorough new book should serve as a warning to those of us invested in democracy. Democracy is hard to maintain, and many of the guardrails that protect it are down (Steven Levitsky aand Daniel Ziblatt, How Democracies Die, 2018). Comparative politics scholarship warns us of the perils of presidentialism (Juan J. Linz, “The Perils of Presidentialism,” Journal of Democracy 1, 1990). As Jacobs and Milkis extensively document, our political system is moving in this direction, to our detriment. Institutional reforms are needed, but achieving them will require the vital center to reassert itself. The question is whether we can reforge some type of elite consensus that can strengthen democracy or will we continue down this road of unconstrained president-centered partisanship. What Happened to the Vital Center? is an important read for anyone interested in these issues.