What political social media messages resonate and get shared? We analyzed the first three months of tweets from Hillary Clinton and Donald Trump since winning their respective nominations and found that messages containing #hashtags, @usermentions, or http://www.websitelinks.com decreased likes and retweets. While these features are intended to increase audience exposure, their presence concurrently increases disfluency – the subjective experience of difficulty associated with cognition. These features make the message less visually clear (perceptual disfluency) and require the translation of symbols and text strings into meaning (orthographic disfluency). Features that improved processing fluency (i.e. embedded images) increased interactions. These findings underscore the importance of fluency in brief word-of-mouth transmissions and suggest strategies for social media users seeking to influence the voting public.