Isn't FB's user base about half the World's population. I don't think it's selected along political lines, more likely the recent use profile is politically bia

Isn't FB's user base about half the World's population. I don't think it's selected along political lines, more likely the recent use profile is politically biased because of different politics across age-groups. Though if you're mixing in Insta', then the effect will be reduced. Frecency of engagement with particular content producers on such platforms might tell you something useful though.