Using panel data, this article examines the democratic benefit of expressing political messages on social media, by looking into the sender effect of information processing. Results suggest people who post textual and visual content tend to elaborate upon information themselves. The effect is different depending upon types of discussion motivations for discussion. Civic intentions such as persuasive discussion motivation led to elaboration about the information, while social discussion motivation did not. The relationship was mediated by news-seeking behaviors. Combining findings, this study proposes a theoretical model that implies a virtuous cycle of information flow on the social media sphere.