标题： 谁在暗中主导？ 国会民主党人在 Bluesky 上的 ERGM 和中心性分析 显示英文标题

标题： Who Leads in the Shadows? ERGM and Centrality Analysis of Congressional Democrats on Bluesky

摘要： 在2024年美国总统大选之后，民主党议员及其支持者越来越多地从X（前身为推特）等主流社交媒体平台迁移到去中心化的替代平台，如Bluesky。 本研究调查了国会民主党人如何在缺乏算法放大作用的平台环境中，利用Bluesky建立影响力网络并传播政治信息。 我们采用混合方法，结合社会网络分析、指数随机图模型（ERGM）和基于变压器的主题建模（BERTopic），分析182名经验证的国会民主党成员之间的关注、提及、转发和话语模式。 我们的研究结果表明，尽管党派领袖如Hakeem Jeffries和Elizabeth Warren在可见性指标中占据主导地位，但像Marcy Kaptur、Donald Beyer和Dwight Evans这样的被忽视人物却占据了结构上的中心位置，这表明在数字党派生态系统中存在潜在的影响。 ERGM结果揭示了意识形态、州和领导力方面的显著同质性，参议院领导层的连接性较低。 主题分析识别出了共同主题（例如，生育权利、外国冲突）和子群体特定的问题，其中The Squad表现出最独特的言论特征。 这些结果展示了去中心化平台重塑党内沟通动态的潜力，并强调了在新兴数字环境中继续对精英政治行为进行计算研究的必要性。 显示英文摘要

摘要： Following the 2024 U.S. presidential election, Democratic lawmakers and their supporters increasingly migrated from mainstream social media plat-forms like X (formerly Twitter) to decentralized alternatives such as Bluesky. This study investigates how Congressional Democrats use Bluesky to form networks of influence and disseminate political messaging in a platform environment that lacks algorithmic amplification. We employ a mixed-methods approach that combines social network analysis, expo-nential random graph modeling (ERGM), and transformer-based topic mod-eling (BERTopic) to analyze follows, mentions, reposts, and discourse pat-terns among 182 verified Democratic members of Congress. Our findings show that while party leaders such as Hakeem Jeffries and Elizabeth War-ren dominate visibility metrics, overlooked figures like Marcy Kaptur, Donald Beyer, and Dwight Evans occupy structurally central positions, suggesting latent influence within the digital party ecosystem. ERGM re-sults reveal significant homophily along ideological, state, and leadership lines, with Senate leadership exhibiting lower connectivity. Topic analysis identifies both shared themes (e.g., reproductive rights, foreign conflicts) and subgroup-specific issues, with The Squad showing the most distinct discourse profile. These results demonstrate the potential of decentralized platforms to reshape intra-party communication dynamics and highlight the need for continued computational research on elite political behavior in emerging digital environments.