Immigration has been one of the most relevant topics during the Brexit Referendum, United States presidential election, and Italian and European Parliament elections (e.g., Zappettini, 2019; Faris, Roberts, Etling, Bourassa, Zuckerman, & Benkler, 2017). In particular, during these events, the anti-immigration-political-groups gain consensus (Muis and Immerzeel, 2017). In this study, we investigate, with a text-analysis of 1000 Italian political leaders' tweets, which topics are associated with negative or positive sentiment toward immigrants. The results show that negative messages are associated, in a logistic regression model, with a populistic communication style, and with conspiracy suspicions. Moreover, a network analysis reveals that anti-immigration messages are associated with security and justice topics, whereas pro-immigration messages are associated with the topics of civil rights, culture, and Europe. Stylistics elements of populist and conspiratorial communication and their relation with the diffusion of anti-immigration contents and related consequences on composition and transmission of values, in social media context, are discussed.