You have it literally backwards. The First Amendment makes free speech an unalienable right. The duty of the government is to ensure that it is maintained at all times. This is a right that is far above and beyond enforcing respect towards others' religion or race.
That’s a violation of his first amendment rights.
Delta needs to be sued for constitutional violation and pay out large punitive damages as well as possibly have its flight carrier status revoked.
The First Amendment only applies to government.
Airlines are not government they are a private business, and they can respond in any way they see fit if you violate their policies.
Businesses can and will ban you as a customer and unless it was due to race religion etc., there's nothing much you can do about it.
You have it literally backwards. The First Amendment makes free speech an unalienable right. The duty of the government is to ensure that it is maintained at all times. This is a right that is far above and beyond enforcing respect towards others' religion or race.