Whistle the Racist Dogs: Political Campaigns and Police Stops

Abstract

Did Trump rallies aggravate anti-Black racism? Using data from nearly 12 million traffic stops, we show that the probability that a police officer stops a Black driver increases by 5.1% after a Trump rally during his 2015-2016 campaign. The effect is immediate, specific to Black drivers, lasts for up to 50 days after the rally, and is not due to changes in drivers' behavior. The effects are significantly larger among racially biased officers, in areas with more racist attitudes today, that experienced more racial violence during the Jim Crow era, or that relied more heavily on slavery. Results from a 2016 online experiment show that Trump's inflammatory campaign speech, although not explicitly mentioning Black people, specifically aggravated respondents' prejudice that Black people are violent. We find that the same words also increase the effect of a Trump rally among racially biased officers. We take this as evidence that although not explicitly anti-Black, Trump's campaign radicalized racial prejudice against Black people -- through a phenomenon known as dog-whistling -- and the expression of such prejudice in a critical and potentially violent dimension: police behavior.

Keywords: police stops, political campaign, racial prejudice

JEL Classification: D73, K42