The trend toward continuous expansion of U.S. post-secondary enrollments was reversed in the 2010s. Using pooled state-level data in between-within models, we examine public higher education enrollment trends during the 2009-2019 period. We emphasize variation in the net associations of covariates by tiers. State economic conditions showed stronger net associations with regional comprehensive and community college enrollments than with research university enrollments. The proportion of 19-25 year-olds in the state population showed stronger net associations on research university enrollments than on enrollments in other sectors. The effects of state-level inequality, under-represented group populations, and Republican-controlled states also varied by tier in ways that align with the dominant orientations among conservative elites. Inequality and Republican Party preferences showed net negative associations with community college enrollments, while the proportion of under-represented groups in the 19-25 population showed net negative associations with research university enrollments.