Those anti-miscegenists would have been quite comfortable with your formulation. It would have fit in perfectly with their worldview.
I'm not sure what you're trying to get at, but in any event, your logic is flawed. It's like saying that because Ku Klux Klan members were against shoplifting, shoplifting is OK.
Or as Ewell Gibbons put it, when told by a socialite that she could never let herself eat Pigweed (delicious, by the way), because pigs enjoyed eating it, "madam, if you refuse to eat anything that pigs enjoy, you'll starve to death" (or words to that effect).
I suppose "those anti-miscegenists" were opposed to people marrying their children too. Shall we now legalize that, simply because "those anti-miscegenists" opposed it?
I was making an analogy, not a deductive argument. No analogy is exact, but the more apt an analogy is, the more persuasive power it has. You'll have to make up your own mind how good my analogy was, but it followed very closely the form and substance of Spunky's statements.
As far as Ku Klux Klan members and shoplifting go, the issue of shoplifting is not a core part of the KKK's identity or beliefs. It would be much more relevant to note that the KKK was against blacks being able to vote or ride in the front of a bus, and the KKK was especially against black men having sexual intercourse (even if consensual) with white women. The latter constituted a beating/hanging/burning offense.
If someone were to argue that gays or Jews or Chinese should not be able to vote or ride in the front of a bus or have consensual sexual intercourse with those outside their groups, and that to do so merited beating/hanging/burning, it would be perfectly proper to analogize those attitudes with the KKK's attitude towards blacks, and thereby denigrate those attitudes.
Of course that approach only works if such attitudes are intrinsic to the nature of the Ku Klux Klan, and if one abhors the Klu Klux Klan...