I would argue that they will, in fact, be the government. The people elected them and the people allow them to continue doing what they're doing. The U.S. was founded for the people and by the people; if the people want the Second Amendment repealed! and the proper steps are taken, then it is, by definition, constitutional.
I never ever said or thought that the government cannot repeal the 2nd Amendment. They most certainly can. When they do, they will no longer be the government. They will at that point be individual people who are enemies of the Constitution of the United States.