Scholars of political parties frequently note that a party's candidates are aided by the presence of a consistent and favourable party brand name. We argue that partisan success in maintaining a consistent position on important policy issues hinges on how their role in the government motivates their strategies about public policy formation. Specifically, when parties share control of government institutions, parties need to balance their electoral interest in promoting a consistent brand name with the need to generate public policy that leads to effective governance. When control is held by one party, the costs and benefits of effective governance are born entirely by the majority, absolving both parties of the need to compromise on the substance of policy. By employing item response theory methods to assess patterns of party voting on deficit issues, we find strong support for these hypotheses.