When studying the political development of young people, level of education matters. However, instead of concentrating on the amount of education and how it affects one’s political attributes (vertical effects of education), we consider the effects of characteristics of one’s education, specifically one’s college major, among people with similar levels of education (horizontal effects). Our study demonstrates that the discipline in which one majors affects one’s political development, over and above the expected self-selection effects. While our results are modest, they suggest that there is much to be gained from exploring horizontal variations in education and its effects on political attributes.