Keywords: Political Parties; Party Ideology; Political Ideology; Party Ideology Development; Ideas.
We know a lot about the essence of the ideology factor in parties' trajectories but remarkably little of how and why this is expressed and translated into the theoretical building blocks that rationalize it. This article takes up this forgotten issue, attempts to locate the concept of party ideology development, clarify its usefulness in the understanding of the relationship between parties and ideologies, outline an effective measurement process and, in doing so, shed light on avenues of research in the comparative study of party politics that so far remain unutilized. The main argument is that although party ideology development has evaded scholarly attention, it remains a germane concept through which we can further disentangle forms of ideological expression. Systematically integrating the development of ideology into the study of party politics can add to our corpus of knowledge about how and why parties adapt and differ between them and can have implications for democratic theory.