Abstract
Sinn Féin's first place in the Irish general election of February 2020 surprised most observers. The party had lost half its council seats in May 2019 and polled at about 14% in October and November. I ask whether Facebook saw the surge coming. Using 297,790 posts from 357 Irish politicians' Facebook pages tracked by CrowdTangle between November 2016 and October 2020, I measure each party's share of the interactions on politicians' pages month by month and compare it with published polls and results. In ordinary times Sinn Féin's share was close to its poll rating: about 20% of interactions in 2018 and early 2019, against polls of 16% to 18%. Measured against votes, Facebook over-represented the left opposition, Solidarity–People Before Profit above all, and under-represented Fine Gael and Fianna Fáil. In the autumn of 2019 Sinn Féin's share rose sharply, from 18% in September to 30% in October and 38% in December, while its average poll rating, adjusted for differences between pollsters, rose from 13% in October to 18% in December and 21% in January. The three-month rise of 12 points was more than twice as large as any earlier rise in the series. But it was not clean. The October jump was concentrated in a few posts and pages, partly around the budget and Brexit; outside the page of Pearse Doherty, Sinn Féin's finance spokesperson, the share fell back in November, and the broad rise began in December. Earlier single-month jumps of similar size were not followed by poll gains, and across 2017–19 changes in Facebook share did not predict changes in the polls. Within the same pages, Sinn Féin posts drew modestly more engagement in October to December than before, an effect of marginal significance and similar to a seasonal rise in 2018. The case offers a qualified answer: an unusually large and sustained shift in Facebook attention came one to three months before most pollsters recorded Sinn Féin's rise, but the same measure has produced false signals, and its level is a poor guide to the vote.Files: the preprint (PDF); monthly posts, interactions and interaction shares by party on Irish politicians' Facebook pages, November 2016 to October 2020; the list of 357 pages with the author's party coding (AI-assisted, provided for checking); and the published Sinn Féin poll ratings used, 2017 to 2020. No post-level data are included.Provenance and AI use. The data were exported from CrowdTangle in October 2020 for my doctoral research. This paper builds on my doctoral thesis (Hotham 2021, University of Bath). The analysis and writing were completed in 2026. The analysis code and drafts of the text were prepared with the assistance of an AI system (Claude, by Anthropic), which was also used to review drafts. I checked the analysis and the text and take responsibility for both. Version 2 added this statement to the paper, and version 3 changes only the date on the title page; the findings are unchanged.
Cite
Hotham, T. (2026). Ahead of the Polls? Sinn Féin, Facebook and the 2020 Irish General Election. Preprint, Zenodo. https://doi.org/10.5281/zenodo.23300887