Influence in the political Twitter sphere: Authority and retransmission in the 2015 and 2016 Spanish General Elections

Candidates, parties, media and citizens have the same ability to post tweets. For this reason, mapping the dynamics of interaction among users is essential to evaluate the processes of influence in an electoral campaign. However, characterising these aspects requires methodologies that consider the interconnections generated by users globally. The discipline of social network analysis provides the concepts of centrality and modularity, both very suitable for the context of network communication. This article analyses the political conversation on Twitter during the 2015 and 2016 General Elections in Spain, in which four candidates with significant popularity in the electorate participated. Two corpora of 8.9million and 9.7million tweets were collected from each campaign, respectively, to analyse the networks of mentions and retweets. The network of mentions appears more blurred than that of retweets, allowing us to better estimate users' partisan preference. The graphs of the network of retweets show a strong internal activity within clusters, and the proximity between them reflects the ideological axis of each party.