This paper shows the extent of the politicism I talked about in "Economics Is Unemotional—And That's Why It Could Help Bridge America's Partisan Divide" and "Twitter Debate on "Politicism" (Political Prejudice)." The experiments seem to have an adequate sample size, and as a result adequate precision, to have some confidence in the results. 

I learned of this paper from Amanda Ripley's June 30, 2017 Wall Street Journal article "America, Meet America: Getting Past Our Toxic Partisanship," subtitled "Bringing back U.S. exchange programs could help remind citizens what we all have in common."