[UPDATE: The first paragraph below flowed from my misreading of S. 1400, which would indeed have set up multiple ages of consent depending on the age of the other party: It would have legalized sex with 12-year-olds when the other party was less than five years older; made it a misdemeanor when the other party was under 21; and made it seemingly a relatively low-grade felony when the other party was 21 or older. That's still a scheme that strikes as too tolerant of sex with the quite young, but at least it's much more comprehensible than a flat age of consent of 12. And this correction makes the rest of this post rather moot, since it leaves only the NCGO's recommendation, which on its own now seems as simply an outlier. My apologies for the error.]
Whatever Justice Ginsburg thought about the recommendation that the age of consent in federal enclaves be lowered to 12, it seems striking by today's standards that such a recommendation would be offered. Yet in 1973, a Senate bill specifically made this suggestion, and as best I can tell it wasn't a part of a scheme in which there would be one (higher) age of consent when adults have sex with minors, and a lower one when two minors who are close in age have sex. The law would have made it legal for adults to have sex with 12-year-olds in federal enclaves (federal territories, federal admiralty jurisdiction, Indian country, at least in those cases where the tribes didn't have jurisdiction), plain and simple.
Likewise, the National Coalition of Gay Organizations' "1972 Gay Rights Platform in the United States" called for "Repeal of all laws governing the age of sexual consent." According to Laud Humphreys, Out of the Closets: The Sociology of Homosexual Liberation 162 (1972), the meeting at which this was adopted was apparently a pretty mainstream event within the liberal activist movement — "[s]upportive telegrams were received from Democratic candidates John Lindsay and George McGovern," which suggests that it wasn't just an entirely irrelevant fringe group.
Can anyone give me a sense of what was going on at the time? Were these just a few isolated events? Did they flow from a broader sexual revolution movement (even if they didn't represent everyone in that movement, and even if many in that movement would draw the line at consenting adults, or at least consenting teenagers-with-each-other-but-not-with-40-year-olds)? Did they come out of a broader children's rights movement, some branches of which believed in children's sexual autonomy rights? (Naturally others in a children's rights movement may support stronger statutory rape laws; again, I'm not speculating that some movement entirely or largely supported these proposals — I'm just wondering what intellectual stream these proposals flowed from.)
Incidentally, I realize that until recently the age of consent in many states was 14, and that even now it's 14 in some European countries (if this site is to be trusted); and I realize that deciding the proper age of consent is a complex matter. But (1) 12 isn't 14, (2) moving to cut the age of consent isn't the same as maintaining a longstanding low threshold, and (3) I'm not asking what the right age of consent is: I'm curious what was the ideological and political movement (if any) that led to the proposals that I mentioned. If anyone has any pointers on this, I'd love to hear them.