In this chapter the concept of generalised competence is used to analyse and explain one of the most significant and yet largely unexplained questions about politics and electoral support. Why do parties so regularly lose public support over their period in office? A pattern of generalised competence is revealed consistent with the "costs of governing", or "costs of ruling". A theory of costs of governing is argued for based on time-varying attribution of blame. Voters' judge incumbent parties' performance in predictable ways - delineated by different time periods. Specifically, the theory argues that newly elected governments experience a largely blame-free honeymoon period, followed by a period of responsibility attribution (and blame) with a bias towards negative information, and the accumulation of blame up until a saturation point where voters have made their minds up on the incumbent and new information is of little use. Support for this theory is found based on analysis of support for incumbents in five countries (the U.S., U.K., Canada, Australia and Germany), in addition to evidence consistent with a "coalition of minorities" explanation, whereby voters punish incumbents for cumulative deviation from public preferences for policy.