You write with as if you are Constitutional scholar however you know that there is no law in the land that allows discrimination based on race, gender, religion, sexual orientation, whether there is public or non public money involved. There is no law in America that can protect a company that discriminates against homosexuals, or blacks, or women, and same goes to landlords, etc.... Since such a law does not exist then your interpretation of the Constitution is very naive and very wrong.
Oh my. You have things *completely* backwards here. Your comment is the equivalent of saying that there is no law in the land that grants you permission to eat crackers in bed and therefore eating crackers in bed is forbidden. Thing is, you don't need a law that allows you to do something before you can legally do it. Asking permission before acting is for children, not for free adults.
The Constitution certainly *doesn't* forbid private parties from discriminating on the basis of race or gender or anything else. There's no need for a "law in the land that allows discrimination". The right to discriminate is the default position. That right was taken away by Acts of Congress, NOT by the Constitution. Don't you get that? Non-discrimination is required by statute, not by anything in the Constitution at all. If the anti-discrimination laws were revoked tomorrow, the default situation, i.e., freedom to discriminate, would return--no permission or law that allows it would be required.
Essentially, what you're claiming is as follows:
That which is not specifically permitted is forbidden.That's the mindset of a slave.