It's For The Children - Do You Hate Children, Sir?
The reason why "for the children" justifications for public policies are so common is because they work, even when (as is often the case) the connection between the policy in question and a benefit to actual children is extremely tenuous.
The reason is rhetorical: To oppose the policy in question is to risk being portrayed as "not for the children," which is not a winning quality for policy debate.
Alas, even the usually even-handed Jim Henley seems to have fallen for this rhetorical trick, agreeing with one of his commenters who wrote,
Absolute NO to Mary Ruwart. Anyone who can’t forcefully deny the legitimacy of child pornography needs to be kept as far away as possible from anything called “libertarian.” That’s not the publicity we need. She could do real damage.
Of course, as Roderick Long explains here, Ruwart was never unwilling to "forcefully deny the legitimacy of child pornography"; she merely had the chutzpah to point out that what counts as child pornography depends on what counts as a child, and what counts as a child for these purposes depends on one's ability to consent, an ability that in reality does not magically burst into existence on every child's 18th (or 21st) birthday, but tends to vary with the individual.
Ruwart’s comments were taken out of context. Now, one can criticize a public figure/political candidate for speaking (and writing) in such a way that one’s comments are likely or at risk of being taken at of context, but the only alternative then is to speak only in soundbites, where nothing of actual substance is ever said.
If libertarians primary and overriding concern is getting elected without any risk of scaring the public, then I agree: stay as far the hell away from people like Ruwart as possible. By even agreeing to analyze and address issues surrounding age of consent, Ruwart risks courting controversy. The only way to avoid that possibility is to refuse to discuss difficult issues; most politicians choose this safer route.
But if our concern as libertarians is not merely to attain political power, but to educate and improve the quality of political discourse, then there is no getting around the fact that in depth discussions do not always make for safe soundbites.
If libertarians are content with letting anyone and everyone get away with using “for the children” as a catch-all excuse, because challenging that rationale means risking being portrayed as “not for the children,” then so much the worse for libertarianism.