Roll call voting data analysis has been challenging using traditional statistical methods. This paper introduces a novel Bayesian approach for spatial models of roll call voting, offering greater flexibility.

Unlike previous techniques that often assume legislators vote sincerely based on policy positions (assumption: sincere voting), this method accommodates various scenarios without such requirements. It handles any legislative setting and works regardless of legislator extremism or the number of available votes.

The Bayesian framework allows for easy extensions, incorporating insights from other sources like party discipline effects or dimensionality changes. Crucially, it provides a coherent way to assess uncertainty and formally compare different models of voting behavior.

This tool is invaluable: Researchers can test alternative political theories, such as log-rolling or strategic voting, directly using roll call data. It bridges measurement challenges with model testing in legislative politics.