This article addresses power-sharing constitutions that include powers of veto wielded by discrete ethnonational groups. Such constitutional arrangements – seen, for example, in Northern Ireland and Bosnia – have often prompted severe deadlock, a problem that in turn threatens democratic functioning and raises the risk of renewed communal violence. We consider the use of ‘umpires’ of power-sharing constitutional systems to vet the use of vetoes and (potentially) to prevent their overuse or misuse. Power-sharing umpires are not uncommon in practice. However, as yet there is little scholarship evaluating how, in substance, power-sharing veto umpires should approach their task. Relying on deliberative democracy theory, the article outlines three forms of ‘deliberative agreement’ that, in principle, deeply divided groups may reach in the course of policymaking. It goes on to explain how existing proportionality doctrines drawn from federalism and rights cases can be imported into the power-sharing context to ‘scaffold’ these broad ideals. This approach, it is argued, may provide a more detailed, coherent and practically workable approach to umpiring power-sharing constitutions.

Several watershed events preceded the dissolution of Yugoslavia. One of these was the toppling of the Vojvodina autonomist leadership in October 1988. This was preceded by a series of rallies throughout Vojvodina in the summer of 1988, which may have seemed like a spontaneous affair and the work of “ordinary citizens.” It was called “the antibureaucratic revolution.” However, these rallies, including a standing group of demonstrators, continually and always referring to the grievances of Kosovo Serbs, turned out to be supported by the Serbian political elite centered in Belgrade. The elite, still headed by the Serbian Communist Chief Slobodan Milošević, gave thrust and coordination to efforts to organize the rallies. The Vojvodina leadership was toppled for their alleged “failing to understand the plight of Kosovo Serbs.” The overthrow was, further, with a view to achieve the Serbian elite’s pet project, the “united Serbia”—that is, doing away with Vojvodina’s and Kosovo’s autonomy. Written sources (including recollections by Yugoslav leaders of the time) and written sources are considered in research on the events.

This article argues that post-conflict consociational arrangements in ethnically divided societies incentivize moderation by political parties, but not policy differentiation outside the main conflict. This results in little policy-driven voting. Analysing party manifestos and voter survey data, we examine the evolution of party policy and cleavage voting under power-sharing in Northern Ireland 1998–2016. We find a reduction in ethno-national policy differences between parties and that ethno-nationalism has become less important in predicting vote choice for Protestants, but not Catholics. We also find little party differentiation in other policy areas and show that vote choices are largely independent of people's policy stances on economic or social issues. Our findings are thus largely consistent with a ‘top-down’ interpretation of political dynamics.