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.

翻译：人们日益担忧，过去十年间，工业化民主国家的政治极化现象日趋严重。事实上，美国、英国、法国和德国的选举均出现了激烈角逐，典型案例包括2016年特朗普与克林顿的总统选举以及英国的脱欧公投。然而，尽管对关键议题的极化现象已有大量定性讨论，但正式的定量评估研究却寥寥无几。因此，本文对2021-2022年间美国国会代表在关键政策问题上的政治极化程度进行了统计评估。该方法基于对推特数据进行情感分析，并针对根据投票记录划分的六个政治群体开展定量分析。研究探讨了两组政策议题，包括地缘政治政策（如乌克兰-俄罗斯、中国、台湾等）和国内政策（如堕胎、气候变化、LGBTQ、移民等）。结果发现，在本文探讨的十二项政策中，枪支管控的政治极化程度最高，所有群体均呈现显著极化（其中四个群体的P<0.001）。其次极化程度较高的问题包括移民与边境管控、化石燃料以及乌克兰-俄罗斯。有趣的是，极化程度最低的政策议题是台湾、LGBTQ和中国共产党，这可能表明这些议题上的两党共识程度最高。研究结果有助于识别跨政治群体的共识领域，从而为未来政策制定提供指导。