Sorry to nitpick, but it is perfectly 100% legal for an old man to take off with an 18 or 19 year old teen in any state. In many situations it's legal for them to take off with a teen younger than that.
As for what the age for emancipation should be, I don't have a good answer for that. But this case proved that a 15 year old girl was mentally capable of making that decision.
The major problem I have with the laws are that it is perfectly legal for a 50 year old to have a relationship with an 18 year old. But if he or she starts that relationship one day before the 18th birthday of the younger person, that could result in a 10 year prison sentence. That is just insane to me.
This case did not in any way prove that a 15 year old was mentally capable of making the decision to go off with her 50 year old teacher. In fact, multiple, repeated posts demonstrate that it is the exact opposite - she was not mentally capable. Hence the laws against allowing such a thing.
As for the age at which it becomes illegal seeming illogical because the day before a kid turns 18 their predator can be sentenced to 10 years, well, it's the grain of sand argument. At what age does a human become adult enough to make rational decisions?
Clearly, that concept has changed. There was an old saying that sounds pretty horrible/racist today, from the 1800's, that illustrates that point - "I'm free, white and 21". Which meant he could do what he wanted. So in the old days, despite many early marriages, parents controlled that an could forbid it. 21 was seen, then, as the age at which a person was mature enough to be free from their parents' yoke.
Today it is 18 in most places, although while people can't drink under 21, they can go to war and die. And while they can't vote under 18, in some states they can marry dirty old men.
It seems arbitrary, but it's not. I feel that any time there is an imbalance of power, whether by age or position of authority or cognitive abilities, it is gross and immoral. Of course not everything that's gross and immoral is illegal. In fact, there is often no societal consensus as to what's gross and immoral!
But when it comes to things like age-related capacity, it is necessary to have a line somewhere. Our culture decides where that line is based on various factors including how we define childhood, the evolution of psychology and advances in science that can tell us how the brain functions. Based on all of that, the line is typically between 16-18 at present in most states, and at the lower end typically with qualifiers.
I think 18 is a good line. And we have to understand that charges against someone who had sex with a minor without force, a day or two before they turned 18, really don't happen unless additional factors are present that make it a particularly disturbing case.
Interestingly, in no state is it less than 16. And I think there are good reasons for that. What age do you feel is appropriate? Or are you saying there should be no line above puberty at all?
I mean right now the law categorizes severity based on age-disparity and age of the victim. What's your opinion if 15 is too old?