Although education for democratic citizenship has long been a powerful rationale for social studies education, researchers still report a significant gap between this purpose and what is really taught in classrooms. Explanations of this phenomenon vary, but literature on citizenship education (CE) research has largely interpreted this gap as a result of (preservice) teachers’ political worldviews or lack of civic experiences. Other evidence, however, suggests that teacher socialization processes generate conventions about what is necessary, possible, and reasonable in CE that go beyond teachers’ political views and behaviors. This mixed-method study, developed at a Spanish university, aims to explore the understandings of CE shared by preservice teachers with different political ideologies and levels of civic engagement. The findings of this study have deep implications for teacher education courses aimed at fostering CE and the curricular inclusion of current social issues.