It's right there in the 1st amendment. "Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; but it's totally cool for them do order private companies to do it on their behalf outside of any created law or legal procedure."

250 years ago, the only forces powerful enough to silence people was a government. Today it's any overpaid twerp who has been taught that opposing ideas are heresy to be crushed on demand.