Collaborating for COVID-19: Using social network analysis to assess legislative collaboration

This study investigates the network of co-sponsorships in COVID-19-related legislation in thee 117th Congress, uncovering a clear partisan divide that aligns with existing literature on increasing political polarization. The data shows strong evidence of partisan homophily, where senators are more likely to cosponsor bills with members of their own party. Co-sponsorship clusters predominantly occur within party lines, with minimal crossover between parties. A block model analysis reveals four distinct roles, with the bridging role mainly occupied by Democrats, except for Republican Senator Susan Collins, known for her bipartisan stance. The network structure highlights two peripheral blocks—one Democratic and one Republican—connected through this bridging block, with isolated nodes consisting entirely of Republicans. This analysis reinforces the notion that contemporary politicians are more polarized than ever, especially in legislative co-sponsorships.