Twitter en campaña. Actores mediáticos en Twitter durante la campaña electoral intermedia en México en el año 2015
From the theoretical approach of Political Communication, this article studies the activity of the profiles of media actors (media, journalists and communicators) who participated in the discussions on Twitter during the last intermediate elections in Mexico in 2015. A quantitative analysis of the case was made from a methodological scheme called Top Discussion Indicator (Percastre-Mendizábal, Pont-Sorribes, Codina, 2017), which allowed obtaining a significant sample of the messages generated during the day of biggest level of interactions in the legal campaign period. As the main contributions to the field of study, this article analyzes the discursive interrelationships between one of the main classical actors of Political Communication (Wolton, 1989) in the space of digital social networks; in addition to the empirical application of a sample selection model of political discussions in a microblogging network such as Twitter.