If the people pass a specific law to take away a particular land owner's freedom of association, force that land owner to associate with someone he would rather not associate with, then the will of the people should prevail because ultimately the people can do anything with their Constitution that they wish.
I would personally not vote for any politician who would force a homosexual land owner to rent out his property to a heterosexual or force a black land owner to rent his property to a white person. I would defend their freedom to associate with whomever they choose.