(though I would challenge you to find a verified source of such a person quoting the Old Testament as justification for their position).
Not very diffecult for anyone that's bothered reading any amount of history on the time period, lets start with a quote by one of the supporters of interacial marriage being illegal shall we?
“Almighty God created the races white, black, yellow, malay and red, and he placed them on separate continents. And but for the interference with his arrangement there would be no cause for such marriages. The fact that he separated the races shows that he did not intend for the races to mix.”
- Judge Leon M. Bazile, Janurary 6, 1959
Notice how the arguement is religious in nature rather then speaking of racial supriority? Lets continue on from there.
"
As Ham is not the father of the negro, and no one asserts that either Shem or Japheth is, then the negro belongs to another race of people, and that he came out of the ark, is a demonstrated fact; and not being of Noah's family, who are white, and Adam and Eve being likewise white, therefore, they could not be the progenitors of the negro; and as neither the name or curse did make Ham a negro, or the father of negroes (and this covers the space of time from now back to the flood and to Noah), and no mesalliance ever having taken place from the flood or Noah, back to Adam and Eve, by which the negro can be accounted for, and Adam and Eve being white, that they could never be the father or mother of the kinky-headed, low forehead, flat nose, thick lip and black-skinned negro; and as Adam and Eve were the last beings created by God on earth, therefore, all beasts, cattle, etc., were consequently made before Adam and Eve were created; and the negro being now here on earth, and not Adam's progeny, it follows, beyond all the reasonings of men on earth to controvert, that he was created before Adam, and with the other beasts or cattle, and being created before Adam, that, like all beasts and cattle, they have no souls."
The Nergo, What is his Ethnological Status? - By Rev.Buckner Payne.
Another example of Old Testament stories being used as an excuse for racial bigotry; tho unlike the first quote, the person in question did believe in racial supriority.
In "Take your Choice: Separation of Mongrelization," written by Sentar Bilbo, he wrote...
"Purity of Race is a gift of God.... and God in his infinite wisdom, has so ordained it that when mans destroys his racial purity, it can never be redeemed."
Another good example of arguements relying on the Christian faith for segregation without relying purely upon racial supriroty to boot. If that's not enough for you, look up a book called Noah's Curse, by Rev. Palmer..... amongst dozens of other similar books, all by different authors that use the exact same biblical-based arguements.
Examples of common bible quotes used by these authors are as follows.
Genesis 28:1: "And Isaac called Jacob, and blessed him, and charged him, and said unto him, Thou shalt not take a wife of the daughters of Canaan."
Leviticus 19:19: "Ye shall keep my statutes. Thou shalt not let thy cattle gender with a diverse kind ..."
Deuteronomy 7:2-3: "And when the LORD thy God shall deliver them before thee; thou shalt smite them, and utterly destroy them; thou shalt make no covenant with them, nor shew mercy unto them: Neither shalt thou make marriages with them; thy daughter thou shalt not give unto his son, nor his daughter shalt thou take unto thy son."
Honestly, I'm somewhat shocked you diden't know about any of this already, but hey, not everyone cares that much about history or bothers to learn about it, so I'll let it pass without picking on it too much.
The exact same crowd of people that where against racial marriage then is now targeting the gay community, same exact bigotry, different minority to pick on. The arguements used by those that are against gay marriage today are nearly identical to the arguements used by those that where against interacial marriage, back then, they cried out that their religious rights where being stepped on, repackaging their own insecurities and bigotry as religious freedom.
Also, like before, this form of intolerance will fall flat on its face; we're already getting there... and for that? I say God bless America, this country is just getting better and better all the time, so stay on the sinking ship of intolerance and bigotry if you want, enjoy the ride, because you're going to end up belonging to a very small and VERY disliked minority yourself... you're already one step in the right direction, the KKK is against gay marriage you know.
http://www.ksla.com/story/4079010/kkk-endorses-gay-marriage-ban-amendment