Political communication research has long sought to understand the effects of cross-cutting exposure on political participation. Here, we argue for a paradigm shift that acknowledges the agency of citizens as producers of cross-cutting expression on social media. We define cross-cutting expression as political communication through speech or behavior within a counter-attitudinal space. After explicating our conceptualization of cross-cutting expression, we empirically explore: its extent, its relationship to political arguments, and its implications for digital campaigning during the 2016 Brexit Referendum. Our dataset, comprising 2,198,741 comments from 344,884 users, is built from Facebook comments to three public campaign pages active during the Brexit referendum: StrongerIn, VoteLeave, and LeaveEU. We utilize reactions data to sort partisans into “Remain” and “Brexit” camps and, thereafter, chart users’ commenting flows across the three pages. We estimate 29% of comments to be cross-cutting, and we find strong correlations between cross-cutting expression and reasoned political arguments. Then, to better understand how cross-cutting expression may influence political participation on social media, we topic model the dataset to identify the political themes discussed during the Brexit debate on Facebook. Our findings suggest that political Facebook pages are not echo chambers, that cross-cutting expression correlates with reasoned political arguments, and that cross-cutting expression may influence the online voter mobilization potential of political Facebook pages.
PDF full text from Publisher