Abstract
Podemos and Vox were both presented to the press in Madrid in the same week of January 2014. Podemos won 8% of the vote at the European election four months later and 21% with its regional allies at the general election of December 2015. Vox won 0.2% in 2015 and 2016, then 11% at the Andalusian regional election of December 2018 and 15% at the general election of November 2019. I ask how each party's share of Facebook engagement related to its support in the polls and at elections, and whether changes in that share came before changes in the polls. I use 58,418 posts from the official national Facebook pages of the main Spanish parties, recorded by CrowdTangle from January 2014 to October 2020, and compare each party's monthly share of interactions on these pages with its share in 1,155 national polls and at seven elections. Podemos drew about half of all interactions from its first weeks, before national polls included it, and 50% in the month before the 2014 European election. Vox's share rose from 4% in 2016 to 15% in the spring of 2018 and 33% to 39% from October to December 2018, while its share in the polls stayed below 3% until the Andalusian result. A typical Vox post drew less engagement than a typical post by the other parties until 2018 and nearly six times as much in 2019 and 2020. After their breakthroughs both parties drew roughly two to five times their share of the vote. Tests of timing are weak. For Vox, a rise in Facebook share over three months was followed by a rise in poll share, but the association comes from the campaign periods of 2018 and 2019 and is absent before the breakthrough. Several earlier jumps in Vox's share were not followed by poll gains. For Podemos, the association appears only at a one-month horizon. Facebook engagement in this period identified the two insurgents' unusual pull on attention, but was a poor guide to the level of their support and an unreliable guide to its timing.Files: the preprint (PDF); monthly Facebook interaction shares and poll shares by party, 2014 to 2020; quarterly median interactions per post by party; the monthly medians of national polls used (computed from the poll compilations on Wikipedia); Facebook and vote shares at seven elections; and monthly summaries of how concentrated Vox's engagement was. 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). Launched the Same Week: Podemos, Vox and Facebook in Spain, 2014 to 2020. Preprint, Zenodo. https://doi.org/10.5281/zenodo.23302075