The representation of citizens and legislators in the same ideological space requires that both employ the same structure to guide their political atti- tudes. Public opinion research has long argued for a differentiation between the two groups. While previous research assumes that legislators closely align their attitudes along ideological dimensions, citizens are said to do so only to a varying degree. In this manuscript, I describe an item response model with group specific error variances that takes this disparity into account. An application of the model to the cooperative congressional election study (CCES) of 2008-2012 shows that respondents’ attitudes about political issues are generally less constrained by underlying dimensions when compared to legislators’ preferences revealed in roll call votes on the same issues. The re- sults further highlight that citizens who closely follow the news about public affairs are more similar to legislators in applying ideology to organize their preferences.

[Working Paper]