A Few More Thoughts On The Christian Faith Position: Human Rights Come From God.
Human rights and the moral code they spring out of originated in the mind of God as objective moral realities prior to the existence of humans. The institution of slavery and Dred Scott, as concepts ugly and immoral, existed in the mind of God as ugly and immoral, say, 999 trillion years prior to human existence and therefore prior to slavery and Dred Scott.
If you can get 51% or 100% of an electorate to agree that the murderous human rights violations of Stalin and Mao were morally justified in order for them to achieve their vision of "the greater good" for their nations, and then get that electorate to elect politicians that will codify their agreement into law, that does not make what the electorate codified morally right and does not establish a legitimate moral right for Stalin and Mao to do what they did to other human beings. Why not? Because human rights, and the moral code they spring out of, originated in the mind and nature of God prior to the existence of Stalin, Mao, your atheistic self, and human kind.
If rights and morality did not originate and does not exist, objective, absolute, and unchangeable, in the mind of God, but rather has originated in the minds of humans who have for 6000 years demonstrated fluxuating and contradictory opinions, laws, whims, preferences, prejudices, intellectual contradictions, moral contradictions, and large laughable amounts of ridiculous political, economic, and social self-contradicting nonsense, then we are forced to conclude that our human moral code and human rights code is at any moment subject to the whims of human Absurdity, in that Human-Majority-Voting and Huge-Powerful-Militaries could, if they wanted to, morally legitimate Dred Scott in January, morally de-legitimate Dred Scot in Feburary, morally legitimate Dred Scot in March, morally de-legitimate Dred Scot in April.
Moreover, if human rights originated and are created by humans as you claim, then human electorial majorities via official proclamation could, anytime they wanted to, morally legitimate the murderous human rights violations of Stalin and Mao in January, de-legitimate them in Feburary, legitimate them in March, and de-legitimate them in April, etc.