Two features of the Indian political system make such disparate electoral coalitions feasible. First, most parties are not deeply ideological, although they may have discernible social or caste bases. In the West, a ‘leftist’ socialist party is unlikely to ally with a ‘rightist’ free market party. Second, most parties are controlled by a few individuals at the top, or a single charismatic leader. This means that forming coalitions across parties only requires the buy-in of a small number of people. Both of these conditions were present in the formation of the Grand Alliance (and NDA) in Bihar.The National Democratic Alliance, led by the Bharatiya Janata Party, suffered a crushing defeat in the 2015 Bihar State election. In the 2014 national election, the NDA won 172 out of 243 Assembly constituency (AC) segments. But in the 2015 Bihar election, just 18 months later, the NDA won only 58 ACs. It is useful to think about how this election informs our understanding of the electorate. Much has changed in Bihar’s political landscape since 2010, when the Janata Dal (United) was in alliance with the BJP under the NDA banner and went on to sweep the State election, winning 206 out of 243 seats. Since then, Bihar has seen a major reconfiguration of party alliances. Just before the 2014 national election, the BJP and JD (U) split over the choice of Narendra Modi as prime ministerial candidate, with the BJP selecting new coalition partners and the JD(U) running alone. The Grand Alliance (JD(U), RJD and Congress) swept to power in 2015. Its success will ultimately depend upon whether such a disparate coalition is able to effectively govern in Bihar. It is often wrongly assumed that voters cannot comprehend the impact of economic policy choices. However, Bihar has a very mobile population due to labour migration across India and abroad, and people are able to observe very different models of development and their consequences. While many States in India have urbanised at a rapid rate in recent decades, Bihar remains the second least urbanised State in India. Joblessness, low private investment, and weak urbanisation are just as observable to voters as State benefits. For all the talk of the role of caste and religion in politics, economic policy is rapidly emerging as the most important axis along which parties and politicians are differentiating themselves. In the 2014 national election, for instance, Modi came to power on the promise of replicating the Gujarat model across India in contrast to the previous Congress-led government, which prioritised centrally-sponsored benefits like those under the Mahatma Gandhi National Rural Employment Guarantee Act (MNREGA). In the West, most voters are believed to base voting decisions on underlying ideological preferences and existing ideological connections to parties, making the outcomes of elections far more predictable. In India, voters use the electoral campaign to assess a party’s promises, the capacity to deliver on those promises, and the strength of the party organisation. This yields large shifts during the campaign. It also suggests that analysts of Indian elections should pay more attention to how parties conduct their campaigns, rather than simply focusing on structural factors such as caste and religion. The Bihar election provides an important snapshot of larger trends in the Indian political system. Electoral volatility has now become a fundamental characteristic of the Indian political system, with shifting party coalitions and changes in electoral support over the campaign. The Indian electorate is increasingly deciding between economic policies that will shape India’s future, and much more effort is needed to understand how voters make these decisions in such a volatile environment.