I can legally deny a person based on their sources of income, I don't rent to people that have to borrow money from the government to pay rent, the scholarship people, I don't have to rent to someone on welfare as our criteria is a working tenant. No laws in Oregon restricting me from not renting to a person that does not have a job. Only thing restricting me is age and familial status.
Prove it in a court of law? You’d be lucky to get into court. Years and years of discovery. One petition after another. Remember, the government has lots and lots of attorneys and they are tax payer funded. Your attorneys aren’t. And, yes, you would need at least one for every one the government put on the case.
The government is a master of this type of litigation. They may recognize they would lose in court but they know they can stall until you either go bankrupt or agree to settle.
For example. During the Clinton administration, a local government bought an old motel with the intent of converting it to a half-way house for those with mental and drug related issues. The local homeowners organized and filed a petition to stop the action. The feds kept them in litigation until they dropped their case and even required them to host a “welcome to the neighborhood party” for their new neighbors. When it was pointed out that the property owners were only exercising their constitutional rights to ‘peacefully assemble and petition their government’, the government responded that the rights of the ‘homeless’ trumped these rights.
Now, just how much would it cost you to defend yourself?
From the description of your rentals, it sounds like you probably have access to a lawyer. Why don’t you ask him
(hypothetically) his advice on posting a sign that you won’t rent to anyone who voted for Obama? Ask him if you could be sued on the basis of disproportionate discrimination? Oh, and, ask him about how much you’d spend on the litigation?
One last thing. Since you’ve discussed this with others (this thread), ask him if that could be the basis for a charge of conspiracy to deny civil rights too?
Notice, the question isn’t whether you’d win but whether you could find yourself in some very messy and expensive issues.