Also, it's 97% of political tweets from US adults that mentioned national politics from June 10, 2018, through June 9, 2019, not 97% of all political tweets (many of which are on behalf of organizations).
We inside wonder how many of the political tweets or memes being shared are from Eastern Europe troll farms. I recently read about a Polish troll farm running “Blue lives matter” groups. The purpose was profit not propaganda like the Russian farms.