What kind of electoral system sustains a politics of firm commitments?

In an age of grand coalitions, and widespread dissatisfaction with them, it is clear that one of the major challenges for contemporary parties is to pursue power without sacrificing the principles by which they define themselves. This points to one of the most important yet neglected criteria by which to assess an electoral system: its capacity to sustain principled partisanship. This paper makes a case for the distinctiveness of this criterion and why it should receive more attention. Drawing on the comparative politics of electoral systems, it examines the kinds of institutional feature relevant to an evaluation in these terms, and what it might mean to make institutions more conducive to a politics of firm commitments.