I don't know about all these democrats, NAMBLA members and liberals stating they believe it is ok to rape children. Indeed we shouldn't be afraid of change, but I think we should stick to tradition in this instance.
From even casual observation, mature sexual decisions are largely avoided for most of your 20s.
No, the line drawn at 18 is arbitrary and a strong case exists that sexual maturity actually occurs for the majority in their 20s. Of course, the line has to be drawn somewhere.