Sometimes it's great to be a lawyer, especially when you are talking about the First Amendment. But since I'm not a lawyer I'll have to use my skills as a Liberal instead and what I've read about the First Amendment to explain this.
The First Amendment protects the rights of individuals to say whatever they want to short of libeling, harassing, or inciting violence. Someone could have the most intelligent opinions or the dumbest and expression of all is protected as long as it does not cause legally actionable harm to others. For instance, you can believe that your next door neighbor is an asshole or have racist opinions about that individual but you can't act upon your beliefs by physically attacking them or damaging their property.
Bankers can have negative views about American Indians but they can't them deny them their services. They cannot foreclose on anyone because they do not like the community to which they belong.