The Libertarians always defend pedophiles by hiding behind the opposition to “for the children” routine. Any attempts to slow the rate of perversion in this country is met with a howl of indignation. They will accept almost every form of government oppression as long as it doesn’t touch porn or drugs. They will defend porn and drugs to the death. That’s why they can’t get elected.
I'm not sure how to stop the "spread of perversion" into this country - using your example, the spread of pornography. I am certain that legislating morality is likely not the way to do it. So long as it involves consenting adults of sound mind...I don't think it should be outlawed - and let me tell you why (at least anecdotally...)
My wife's friend is a raging liberal. We're talking kook, lunatic fringe here. She's works as Assistant Dean of Students at a large university. Not long ago she was discussing a Baptist Student Organization that she had more-or-less chased off campus....she just used the existing regs at hand to make it so that it was more convenient for them to meet in a church immediately off campus, rather than right on it. She was pretty proud of her accomplishment, because they were "Intolerant Bigots" and "Wierd".
Her next topic of discussion was the new LGBTQ center that she was promoting on campus, and how proud she was of it. (if you don't know, LGBTQ is Lesbian, Gay, Bisexual, Transgender, and Questioning...)
I stopped her right there and said something like..."You want to get rid of Baptists because they're 'wierd', but yet you fully support people who don't know WHAT SEX THEY ARE!!!!???" She said, "Yup", without a trace of smugness or sarcasm. She had absolutely no concept of the dichotomy of thought, and was certain that what she was doing was completely correct.
Intolerance and religious zealotry are not the sole domain of the right, I'm afraid. And I think that backing either side's moral standards with legislative might is generally a bad thing. As for me, I always am very very dubious about people that do things "For My Own Good", because they'll do them with a completely clear conscience.