Mixing messages: How candidates vary in their use of Twitter.

How do candidates campaign on social media? To date, political scientists have mostly considered the content or tone of candidates' social media posts. In this paper, we combine these research areas and study how candidates' campaigns vary the content and tone of their messages. We argue incumbents emphasize positive issue content and limit attacking their opponent. Competitive races encourage positive mobilization posts and aggressive attack messages. Using Twitter data from the final two months of the 2018 U.S. midterm elections, we find that candidates predictably emphasize different types of messages and, in the aggregate, campaigns' social media feeds significantly vary. [ABSTRACT FROM AUTHOR]