Study finds partisan congressional speech shifts with platform

Members of Congress tend to use more politically polarizing language in forums that are more likely to attract a national audience, according to a new study co-written by a University of Massachusetts Amherst public policy researcher. The findings provide fresh insights about ideological and political rhetoric, particularly on social media, and illustrate that assessing politicians' views based on a single venue is insufficient.

The study appears in the journal Political Research Quarterly.

Kelsey Shoub, assistant professor of public policy at UMass Amherst, found that lawmakers' positions often shift within the confines of what is acceptable within their respective political party, based on venue. In a review of official tweets, Facebook posts, e-newsletters, news releases and one-minute House floor speeches for the 116th U.S. Congress, the research shows that, on average, members used more polarizing language in social media posts and the least polarizing language in newsletters and floor speeches.

"While it is easy to separate Democrats and Republicans analyzing their statements on these platforms, their intra-party positions vary depending on the medium they're using," Shoub says. "This helps to explain the cultlike following of some members who use social media to offer fiery takes on national issues."

The 116th Congress (Jan. 3, 2019–Jan. 3, 2021) encompassed the 2020 presidential election, when partisanship was on full display, Shoub says. While members of Congress are more likely to deviate from their party leaders and exhibit less partisanship during midterm elections, she expects the political rhetoric on social media to increase in the run-up to Election Day 2024.

To reach their findings, Shoub and co-authors Jon Green of Duke University, Rachel Blum of the University of Oklahoma and Lindsey Cormack of Stevens Institute of Technology used multinomial inverse regression, a machine-learning technique, to analyze nearly 800,000 publicly available statements by 440 legislators across the five venues. Each statement was scored based on the use of partisan language relative to other statements in that venue.

Adding to the understanding of political polarization, the study builds on research that has documented that lawmakers often present themselves in different ways to different constituencies on the campaign trail. For instance, a member with an outsized national presence may use more extreme rhetoric on social media but communicate a more moderate message to constituents in e-newsletters or colleagues on the House floor.

"If you're only going by social media, the world will look so much worse than it actually is. That is why we must look at multiple venues to get a more complete picture," Shoub concludes. "That said, it is very easy to identify Democrats and Republicans by only looking at their statements in any of the venues we studied."