A common understanding in public opinion studies is that we, the public, often turn to mental shortcuts to form an opinion on important policy issues: in particular, we reflexively adopt the positions of the political parties with which we identify. The use of political heuristics is prevalent especially when the topic is highly politicized or technical (i.e., cognitively demanding), such as is the case in climate and energy policy. However, recent research on climate beliefs has shown that not only opinions but even our supposedly objective knowledge about the topic correlates with our political ideology. Moreover, research shows that these innocent and natural mental shortcuts may lead us to think we know (subjective knowledge) more than we do. Much of existing research in sustainability transitions has focused on the effect of policy-related information or its framing on public support for a hypothetical policy that is designed to achieve climate and sustainability goals. In reality, however, the amount and type of “relevant” information people seek is not exogenous as it is assumed in many of these studies. Instead, as marketing research has shown in the context of people’s product choice, our objective and subjective knowledge influence how much and what type of information we seek. This is why we argue that the potential effect of political heuristics on our knowledge-building is concerning whether or not our political parties espouse accurate information. In this paper, we investigate whether and under what conditions our perceived or factual knowledge might be influenced by our ideological predispositions.