For U.S. presidential elections, most states use the so-called winner-take-all system, in which the state’s presidential electors are awarded to the winning political party in the state after a popular vote phase, regardless of the actual margin of victory. Therefore, election campaigns are especially intense in states where there is no clear direction on which party will be the winning party. These states are often referred to as swing states. To measure the impact of such an election law on the campaigns, we analyze the Twitter activity surrounding the 2020 US preelection debate, with a particular focus on the spread of disinformation. We find that about 88% of the online traffic was associated with swing states. In addition, the sharing of links to unreliable news sources is significantly more prevalent in tweets associated with swing states: in this case, untrustworthy tweets are predominantly generated by automated accounts. Furthermore, we observe that the debate is mostly led by two main communities, one with a predominantly Republican affiliation and the other with accounts of different political orientations. Most of the disinformation comes from the former.

对于美国总统选举，大多数州采用所谓赢者通吃的制度，即在全民投票阶段后，该州的总统选举人被授予该州获胜的政党，而不管实际的胜利优势如何。因此，在没有明确指示哪个政党获胜的州，竞选活动尤其激烈。这些状态通常称为摇摆状态。为了衡量此类选举法对竞选活动的影响，我们分析了围绕 2020 年美国选前辩论的 Twitter 活动，特别关注虚假信息的传播。我们发现大约 88% 的在线流量与摇摆州相关。此外，共享不可靠新闻来源的链接在与摇摆州相关的推文中更为普遍：在这种情况下，不可信的推文主要由自动帐户生成。此外，我们观察到这场辩论主要由两个主要社区主导，一个主要是共和党，另一个则有不同的政治倾向。大多数虚假信息来自前者。