How similar are politicians to those who vote for them? This is a critical question at the heart of democratic representation and particularly relevant at times when political dissatisfaction and populism are on the rise. To answer this question we compare the online discourse of elected politicians and their constituents. We collect a two and a half years (September 2020 - February 2023) constituency-level dataset for USA and UK that includes: (i) the Twitter timelines (5.6 Million tweets) of elected political representatives (595 UK Members of Parliament and 433 USA Representatives), (ii) the Nextdoor posts (21.8 Million posts) of the constituency (98.4% USA and 91.5% UK constituencies). We find that elected politicians tend to be equally similar to their constituents in terms of content and style regardless of whether a constituency elects a right or left-wing politician. The size of the electoral victory and the level of income of a constituency shows a nuanced picture. The narrower the electoral victory, the more similar the style and the more dissimilar the content is. The lower the income of a constituency, the more similar the content is. In terms of style, poorer constituencies tend to have a more similar sentiment and more dissimilar psychological text traits (i.e. measured with LIWC categories).

翻译：政治家与投票支持他们的选民有多相似？这是民主代表制核心的一个关键问题，在政治不满和民粹主义抬头之际尤为重要。为回答此问题，我们比较了当选政治家与其选民的线上话语。我们收集了为期两年半（2020年9月至2023年2月）的美国与英国选区层面数据集，包含：（i）当选政治代表（595名英国议会议员与433名美国众议员）的Twitter时间线（560万条推文），（ii）选区居民在Nextdoor平台的发帖（2180万条帖子，覆盖98.4%的美国选区和91.5%的英国选区）。研究发现，无论选区选举的是右翼还是左翼政治家，当选政治家在内容与风格方面与选民的相似程度总体相当。选举胜利幅度与选区收入水平则呈现更细微的图景：选举胜利优势越小，风格越相似而内容差异越大；选区收入越低，内容相似度越高。在风格维度，较贫困选区的情感表达更趋相似，但心理文本特征（即通过LIWC类别测量）差异更大。