This study is amusing. The respondent group is 88% white people, 91% of the total group self-identifying with the literal string "liberal". Less than 1% latinx, less than 1% blacks, less than 1% identifying by the literal string "conservative". On top of that respondents were only targeted by Facebook and Twitter posts.

I guess it should be no surprise white liberals that respond to Facebook and Twitter posts are removing themselves from the gene pool. But maybe it's not only them as other demographics are highly underrepresented in this study.