Mapping the e-petition ecosystem through Social Media: mobilization in the EU across issues and ideologies

We study petition-related mobilization on Social Media across issues and ideologies. Using calls to sign petitions on X in the seven most spoken EU languages, we build the first multi-platform, multi-language map of the e-petitioning ecosystem. To ensure cross-language and cross-ideology comparability, we infer call for signatures’ issues using ManifestoBERTa and users' ideological orientation via Ideology Scaling methods calibrated using expert survey data. We classify active individuals into a