Trump whines that they are anti-conservative. I think the bias is in favor of the Republicans since Facebook and Twitter have let him spread thousand of lies and other inappropriate comments most people could not get away with. He’s just trying to bully them into keep allowing his lies. This is all his response to one effort by Twitter to highlight facts on voter fraud. Otherwise, they’re letting him lie. His voter fraud lies are dangerous and will cause his cult members to question the results of the election if Trump loses. Facebook has made it clear they will just let Trump lie. I think both companies are concerned that the government would try to break them up since they are so large and powerful now. That’s my view of why they have let Trump lie. This is another example of Trump’s authoritarian tendencies.