In this special issue of Science, a series of Insights pieces examines the current state of democracy worldwide. "20 years ago, it seemed inevitable that democracy would reach every corner of the globe," write Science Senior Editor Brad Wible and Science Associate Editor Tage Rai, in an introduction. "In this moment we are reminded that we must fight for democracy and work to improve it." Wible and Rai make the stakes clear: "A scientific understanding of the social and behavioral phenomena that underlie [democracy's] operation will help us enhance democracy and, by doing so, improve human lives and societies globally." In a Perspective, David Nickerson and Todd Rogers discuss how political campaigns, which can raise and spend hundreds of millions of dollars each election cycle to maximize the chances of victory, have far less influence on real-world election outcomes than it may seem. A Policy Forum by Wendy Cho and Bruce Cain reviews the topic of gerrymandering, which artificial intelligence (AI) has been proposed to help alleviate. Cho and Cain argue that leaving redistricting to the machines does not guarantee a fair outcome; the role of AI is to augment human capabilities by regulating nefarious intent with increased transparency, they say, and human-AI collaboration is key. In a second Policy Forum, Vesla Weaver and Gwen Prowse highlight a phenomenon overlooked by scholars of U.S. politics; namely, that when authoritarian modes of governance are concentrated on racialized and historically oppressed Americans, they are rarely seen as violations of democracy. According to the authors, this type of governance - including violent police responses to peaceful protests - may provide an opportunity for more traditional forms of fascism to grow, leaving some segments of the population to experience differential citizenship. Weaver and Prowse propose ways to improve how democracy operates in policed societies. In the first of four Reviews, Rohini Pande asks if democracy can work for millions of the world's poorest living in "middle-income" democracies where citizens have yet to use their vote to ensure adequate redistribution of wealth. Since the political voice of the poor is often limited by social and economic disadvantages, Pande argues that the democratic state needs to be reformed so that it can better serve these populations. A second Review by Deen Freelon and colleagues highlights the differences between online activism from both the political left and political right. It's clear that left-wing and right-wing activists use different socio-technical channels and methods to organize and spread their messages, and such ideological asymmetries, say the authors, hold critical implications for democratic practice and social media governance. Delia Baldassarri and Maria Abascal discuss social cohesion in multi-ethnic societies in a third Review. They argue that fostering prosocial behavior within such societies requires economic inclusion. In the final Review, Susan Hyde provides an overview on how the growth of democracy around the world has slowed, and in some cases, declined. This is an important time for scholars to study "democratic backsliding," she says; as compared to past decades, when support for democracy was more roundly felt worldwide, the precipitous decline in international support for democracy in recent years should provide new insights into important questions, including which cases that had previously been interpreted as democratization were illusory to begin with.