  There is growing concern that over the past decade, industrialized democratic
nations are becoming increasingly politically polarized. Indeed, elections in
the US, UK, France, and Germany have all seen tightly won races, with notable
examples including the 2016 Trump vs. Clinton presidential election and the
UK's Brexit referendum. However, while there has been much qualitative
discussion of polarization on key issues, there are few examples of formal
quantitative assessments examining this topic. Therefore, in this paper, we
undertake a statistical evaluation of political polarization for
representatives elected to the US congress on key policy issues between
2021-2022. The method is based on applying sentiment analysis to Twitter data
and developing quantitative analysis for six political groupings defined based
on voting records. Two sets of policy groups are explored, including
geopolitical policies (e.g., Ukraine-Russia, China, Taiwan, etc.) and domestic
policies (e.g., abortion, climate change, LGBTQ, immigration, etc.). We find
that out of the twelve policies explored here, gun control was the most
politically polarizing, with significant polarization results found for all
groups (four of which were P < 0.001). The next most polarizing issues include
immigration and border control, fossil fuels, and Ukraine-Russia.
Interestingly, the least polarized policy topics were Taiwan, LGBTQ, and the
Chinese Communist Party, potentially demonstrating the highest degree of
bipartisanship on these issues. The results can be used to guide future policy
making, by helping to identify areas of common ground across political groups.
