The 2016 election of Donald Trump focused people's minds on populism, and most of the attention paid to the subject since has been on the threat it poses to wealthy democracies. In Democracy Unmoored, Samuel Issacharoff takes a far wider-angle view of the phenomenon, covering countries from across the globe: Brazil, Poland, Argentina, Turkey, India, Hungary, Venezuela, and more. Just as importantly, he focuses on populism's attack on the institutions of governance. Democracy requires two critical features: first, a commitment to repeat play such that political actors understand that what goes around comes around; and, second, institutional constraints so that the majority can prevail, albeit not by too much. Democracies must avoid the doomsday scenario in which the contending parties see the next election as the final choice between salvation and perdition. Issacharoff shows how populist governance undermines each of these two critical underpinnings of stable democracy, first by compressing the time horizon to the immediate, and second by eroding institutional constraints on strongman rule. At the same time, Issacharoff highlights the fact that ascendent populists were pushing in an open door as they found democracies in states of disrepair in the post-2008 world.