Previous studies of U.S. political polarization have examined state-level convergence and divergence. Increasingly, scholars have turned from state-level analyses to regional analyses and advanced claims as to whether regions are becoming more similar or dissimilar. Yet, formal testing has remained largely absent. Using panel unit root tests, we determine whether regional political convergence is occurring between 1970 and 2004. Our results suggest the importance of distinguishing between ideological convergence and partisan convergence. We find the four regions and eight subregions are stochastically converging to a national norm in regard to ide-ology but not with regard to partisanship. Convergence for partisanship is, however, occurring within three of the regions, but not within the Midwest.