First of all, freedom of speech and the press have already been compromised somewhat, namely through the works of the Supreme Court.

But see, you miss my point. My point is that once you say that the definition of something is changeable, you can't then say it can never be changed again. If we make the mistake of saying that marriage is whatever we want to be, who knows what it will change into. And as I said, it could conceivably be expanded to include polygamy, incest, and beastiality as "marriages".

And you can't say that will never happen, because the slippery slope theory suggests it might.