American unions experienced significant decline from 1983 to 2014, spreading geographically despite state-level political leanings. This study shows union weakness in one state is associated with neighboring states' unions weakening during this period.

Key Findings:

* Union decline was observable across multiple states simultaneously.

* Democratic power in Congress correlated with higher unionization rates nationally, but not necessarily preventing decline.

* Liberal state governments proved insufficient to counteract national trends affecting union organization laws and collective bargaining.

This research highlights how federalism structure allows local political shifts to impact the broader trajectory of unions. The findings suggest that while some states may resist union decline through policy, external factors like national politics or cross-border competition likely outweigh these localized efforts.