However well-intentioned this idea, it is simply wrong.
1) We are attempting to reach as many people as possible. If we require NRA or GOA, etc. membership, all that will be done is to preach to the choir. How do you reach fence-sitters who come here with questions?
2) I, for one, recoil at the idea of forced membership on any internet site. That's why I don't subscribe to any sites - this is a national or international conversation, and I won't pay for the "privilege" of spouting off, let alone merely lurking.
Regarding "How is it different this time?":
1) The people in the Warsaw Ghetto didn't know until it was too late what was happening. Ditto most of the victims of German genocide, Jewish or not. Now we know the depths to which human morality can fall, and we can be prepared accordingly.
2) America ain't Europe - we have guns, LOTS of them, and a history of using them against tyrants. In addition, we know how to use them - unlike most of those rounded up and murdered in Europe. I'd say that most of the people on THR or other gun sites would only give up their guns when the guns have a higher temperature than their bodies. The oppressor will bleed rivers of blood before he even begins to approach "success" in his operations - and the leaders would not be exempt, just as animals like Heydrich were not immune during WW2.