The legislative cost of ruling: Voter punishment of governing parties fuels legislator party dissent

Political parties in office generally incur a cost of ruling among the electorate. This article considers the broader implications of this phenomenon for democratic governance. We argue that the electoral cost a party incurs in office entails that its individual legislators become more inclined to vote against the party line as a way to distance themselves from the deteriorating party brand. We test and support several observable implications of this argument using time series data including all members of parliament in the British parliament between 1992 and 2015 coupled with monthly opinion poll data. The well-established electoral cost of ruling thus translates into a legislative cost of ruling by reducing incumbent party legislators’ loyalty to the party line. We discuss how the legislative cost of ruling complicates effective governance but may also strengthen democratic accountability by reducing legislative capacity of governing parties that have lost their electoral mandate.