Vibrant labor movements have long sustained strong workers’ parties, and a nascent environmental movement in Europe gave birth to green parties. Presumably then, social movements aimed at improving the lot of marginalized ethnic groups should bolster the fortunes of ethnic parties targeting those groups. Not so, argues Amit Ahuja in his exciting new book, Mobilizing the Marginalized. Ahuja’s study of Dalits—a collection of castes defined by the historical experience of untouchability and formally termed “Scheduled Castes” by the Indian government—starts with a puzzle. The places in India where social movements first addressed Dalit marginalization have, so far, produced unsuccessful Dalit ethnic political parties. In contrast, Dalit ethnic parties thrive in places where such movements have been largely absent.

In this puzzle lies an answer. The process of social mobilization forces all political parties to take Dalits seriously: to actively solicit their votes, to include them in party networks, and to invoke their symbols and stories during campaigns. Faced with multiple parties that earnestly court their support, Dalits split their votes across many parties, depriving would-be Dalit ethnic parties of enough votes to succeed. Unexpectedly, therefore, Dalit social movements undermine the electoral prospects for Dalit parties.

Instead, Dalit parties arise in places where they have historically been un(der)mobilized and existing parties have done little to truly incorporate Dalit voters. When Dalit parties emerge in areas that lack Dalit social movements, they compare favorably to existing parties, and Dalits shift their votes en masse to Dalit parties. Ahuja further argues that mobilization through social movements has produced far better social and economic outcomes for Dalits than has political mobilization by Dalit parties. After all, when Dalits vote as a bloc for a Dalit party, they are captive clients. Because all parties see their vote choice as a foregone conclusion, Dalits are poorly positioned to make demands on other parties or even hold their own parties accountable. Implementation of pro-Dalit policies also suffers when a Dalit party loses power. Empirically, the book compares four Indian states: two with historically strong Dalit movements and weak Dalit parties (Maharashtra and Tamil Nadu) and two with weak or absent Dalit social movements but some of India’s strongest Dalit parties (Bihar and Uttar Pradesh).

Mobilizing the Marginalized does a number of things exceptionally well. First, it presents a theoretical argument about the link between ethnic social movements and ethnic political parties that is logical and persuasive yet not immediately obvious. From one chapter to the next, the book methodically tracks its theoretical argument. It first details variation in levels of Dalit social mobilization and the immediate consequences of such mobilization. It next shows how those political implications shape levels of Dalit bloc voting, which in turn explain the success of Dalit parties. The book then examines the welfare implications of Dalit social mobilization versus Dalit political mobilization into ethnic parties.

Much of what makes Ahuja’s argument so persuasive lies in the book’s second strength: its simultaneous grounding in the relevant comparative literatures (on social movements and marginalized groups) and the empirical reality of Dalit politics in India. For instance, Ahuja frequently references the well-developed literature on African-American politics in the United States. At the same time, the book remains intimately tied to its subject, never feeling as though it is trying to fit an elegant theoretical claim onto unfamiliar terrain. Indeed, even though the book’s organization follows the argument’s theoretical logic, Ahuja manages to do justice to his cases, providing rich descriptive accounts that will satisfy readers with a keen interest in Dalit politics in his four case-study states.

Third, since “political scientists who examine electoral and party mobilization pay little attention to social mobilization, while sociologists who study social movements often neglect political parties” (p. 7), the book embarks on an important intellectual enterprise that crosses disciplinary boundaries. No wonder, then, that Ahuja arrives at an argument differing from much prior research that emphasizes how social movements sustain, rather than undermine, allied political parties. Finally, Ahuja expertly relies on an eclectic array of evidence, ranging from public opinion data to a survey experiment to sustained field research that includes scores of interviews and focus groups. Ahuja deftly distills lessons from his extensive fieldwork, which helps make this a volume of serious scholarship that is unusually readable and accessible. If there is a downside to this distillation, it is that Ahuja may leave some readers eager to hear more from his interview respondents and focus group participants. When we hear their voices directly, they provide particularly evocative evidence in support of the book’s claims.

In developing an innovative theoretical argument backed by careful case studies of four large states (whose combined population totals nearly a half-billion people), some aspects of the book receive less attention. In particular, a more extended treatment of alternative explanations would, at times, have been helpful. For example, chapter 4 focuses on the consequences of Dalit social mobilization, emphasizing how in “movement states” (those with early Dalit social movements), caste boundaries are policed less stringently, untouchability is practiced less often, and Dalit assertion is more widespread than in “non-movement states” (that historically lacked such social movements). These outcomes very plausibly result from the presence or absence of earlier Dalit social movements. However, the movement states are also wealthier, better educated, and more urban, meaning that we might expect to see meaningful differences between these states on these various dimensions even without taking social movements into account. A more explicit testing of possible alternatives would potentially allay a skeptic’s concerns that differences in Dalit life across these states may be principally a function of urbanization or economic development.

In a similar vein, one may wonder how Ahuja’s noteworthy contribution relates to Kanchan Chandra’s influential 2004 book, Why Ethnic Parties Succeed, which similarly focuses on Dalit ethnic parties. Interestingly, the books share a key insight: ethnic parties cannot claim a natural monopoly on co-ethnic votes. They monopolize co-ethnic votes only when other parties fail to incorporate members of the ethnic group. Chandra’s notion of inclusion emphasizes relatively high-profile leaders, such as legislative candidates, whereas Ahuja’s understanding of inclusion focuses on local party workers and symbolic politics. The two accounts also diverge in their diagnosis of what leads non-Dalit parties to take Dalits seriously—Dalit social movements for Ahuja and intraparty democracy for Chandra (albeit with an added twist in the case of India’s Congress Party). Ahuja addresses Chandra’s argument about intraparty democracy (p. 151) by pointing out that few Indian parties are internally democratic, but throughout the book, it is not always clear where the two authors’ claims represent distinct but ultimately complementary accounts and where they are fundamentally at odds. Many readers would likely have benefited from a more extended discussion of whether or how to reconcile the arguments in these two important works.

All told, Mobilizing the Marginalized constitutes a fascinating, well-argued, and richly detailed account of how social mobilization shapes ethnic party success. It fine-tunes our understanding of the link between social movements and political parties, the relationship between descriptive and substantive representation, and the politics surrounding one of the world’s largest and most important marginalized groups.