These results make clear that the collateral consequences of policing—including worsening outcomes for economic security, educational attainment, and health—also extend to political participation. If the communities who are most frequently subjected to policing are also discouraged from voting as a result, it could create a vicious feedback loop of political withdrawal.
Why would traffic stops make people less likely to show up to the polls? Past research has already established that the most disruptive forms of criminal legal contact, like arrest and incarceration, discourage people from voting. Our study shows that low-level police contact matters in the same way. If a traffic stop makes a motorist fear that the government will harm them, it can prompt a withdrawal from civic life that political scientists call “strategic retreat.” Motorists might worry that a routine traffic stop could escalate into police violence, a more common outcome for Black people in particular. Beyond justified fears of violent victimization, voters might also bristle at the perception of being targeted to raise revenue through excessive ticketing. Accordingly, if incarceration ‘teaches’ would-be voters that their government is an alienating and harmful force in their lives, traffic stops could catalyze a similar form of ‘learning.’
Relatedly, here’s a research paper I saw a few years ago that found that just being stopped by police shortly before an election had a statistically significant association with being less likely to turn out in that election (archive link).
One of the researchers of that participated in a reddit thread that was really fascinating which you can find here - https://archive.is/oDSkv
They also wrote up a summary for a magazine (archive link), which has these two paragraphs that I think explain a lot of why we have red states in this country -