Pay attention to this! Explaining emphasis in legislative speech using automated video analysis in the US House of Representatives


Why do legislators sometimes deliver passionate speeches and sometimes tedious monologues? We argue that legislators make passionate appeals when they want to signal support or opposition to a bill. Whether legislators choose to send such a signal depends on the preference of the median voter in their districts. We expect legislators to deliver more emphatic speeches if their floor vote is aligned with the preferences of their electorate. To test this argument, we apply automated video analysis to plenary recordings of speeches on key votes in the 111th–115th US House of Representatives (2009–2018). We match the speech emphasis with district preferences on the bills using data from the Cooperative Congressional Election Study. We find that House members who rise in opposition to a bill give more passionate speeches when public preferences are aligned with their vote choice. The paper discusses the implications of these findings for our understanding of legislative debates.