Trust, tribalism and tweets: has political polarization made science a “wedge issue”?

Abstract

Political polarization remains a major obstacle to national action on global climate change in the United States Congress, and acceptance of anthropogenic drivers strongly differs between Republicans and Democrats. But has overall interest in science also become ingrained into partisan identity, even among national political figures tasked with making ostensibly science-based policy decisions? Social media outlets such as Twitter have become a popular means of exchanging information and of portraying a carefully crafted public image. We analyzed the 78,753 unique Twitter accounts followed by U.S. senators to gauge their interests as well as the public images that their offices project to the public. In particular, we examined correlations between follows of science-related accounts and recent votes on a series of amendments defining the “sense of the Senate” on global climate change (GCC). Drawing from these social networks, we discuss how political polarization is strongly linked with the role that science - and climate science in particular - plays in the political process. Our analyses show that Twitter social networks reflect political affiliation and polarization, with Senate Republicans and Democrats belonging to distinct and semi-isolated sub-networks. Notably, while follows of science-related organizations were low overall, these sub-networks were characterized by very different levels of interest in science, with Senate Democrats three times more likely to follow science-related Twitter handles than Republicans. This suggests that overt interest in science may partly define party identity. Hence, instead of being viewed as a neutral source of objective information, science may now be considered a special interest in U.S. politics. Notably, however, Republican senators who crossed party lines to vote “yea” on an amendment associated with the Keystone Pipeline bill stating that humans contribute to GCC are more similar to Democrats in their science follows than they are to their fellow Republicans. Our results strongly suggest that overt interest in science may now primarily be a “Democrat” value. However, opportunities exist to inject scientific information into political discussion by targeting key individuals and organizations connected to both sides of the aisle.