There's a difference between disagreeing with a position and finding it "abhorrent".
Your evidence with regards to interracial marriages does not support your point. Whether "something can be discussed" is an entirely different question than than "do you support position X". The very fact that they were able to take a poll is strong evidence that talking about it was not verboten.
This is simply not true, and a strange argument. Child pornography is discussed because people find it abhorrent. US politics has largely revolved around the prevention of interracial relationships for at least a century and a half, so the idea that people didn't (and don't) find them abhorrent is bizarre and ahistorical.
Your evidence with regards to interracial marriages does not support your point. Whether "something can be discussed" is an entirely different question than than "do you support position X". The very fact that they were able to take a poll is strong evidence that talking about it was not verboten.