Susan, what a trenchant criticism of my hypothetical platform language. How dare I suggest that a libertarian platform declare to a community that crossing certain lines constitutes a violation of individual rights. Whatever was I thinking? Well, with any luck you'll get elected to LNC and put a stop to this sort of thing. :-)
There's nothing magical about the numbers 14 and 18. I could live with 13-17, or 15-18, or anything in that neighborhood. I'm not talking about a bright line. I'm talking about a rebuttable presumption, that would be applied by juries to fit the evidence of each case. This idea is old and rather obvious, but I'll credit Tom Knapp for making it more prominent last fall:
http://knappster.blogspot.com/2007/10/blast-from-past-age-of-reason.html . He writes "Somewhere around the age of twelve, my personal arbitrary presumption begins to shift [...]" and proposes to embed that rebuttable presumption into law. Will he be the next target of your sarcasm, or am I as special as my mother always told me? :-)