An extensive body of research shows that citizens’ opinions about political matter are often driven by positions of political parties on particular issues. This paper builds on existing source cue research and tests the effects of party attachments on citizen’s evaluation of policy proposals in a multi-party system. An experimental study tests whether positive and negative affective attachments towards parties influence how voters evaluate policy proposals proposed by these parties. Further the study focuses on possible mechanisms of source cue effects. Source cues may work either as a heuristics, when voters use the party as a shortcut for making judgment about policy. Heuristical thinking reduces cognitive efforts made by citizens in inferences about politics. On the other hand source cues may enhance citizens’ cognitive effort and deliberative thinking if a cue triggers motivated reasoning. We assume that the character of the policy issue influences the way citizens use source cues. When thinking about technical issues with low salience citizens may use party cues as a shortcut. In case of salient political issues authorship of a proposal may motivate citizens to effortful reasoning about the issue. We measure cognitive effort using response latency.
