Content Demotion and Shadow Banning if based on political bias converts internet platforms into publishers. A platform is not responsible for the content shown on their servers. Publisher are liable for the contents including hate crime, defamation and other incitements.
https://youtu.be/Ogx1XjogSkY?t=3519
Section 230 of the CDA immunizes internet platforms from any liability as a publisher or speaker for third-party content.