This thesis examines the relationship between professionalism and careerism in U.S. state legislatures. It challenges the conventional wisdom that professionalism causes careerism in state legislatures, and uses Christopher Mooneys 1995 ordinary least squares (OLS) regression model, with a new careerism variable, to assess this challenge. Results from this model fail to indicate that careerism has a causal effect on professionalism. Rather, the results show that there is a strong positive correlation between professionalism and careerism. These results also hint that the relationship between careerism and professionalism is more complex than previous research has concluded and that the relationship requires additional research, especially using methods such as two-stage least squares (2SLS).