The people created a amendment process for changing their United States Constitution. There isn't any alternative to that amendment process. If the people's amendment process isn't good enough for some folks, well, that's why we have cemeteries.
The Civil War is over, buddy.
Slavery was a legal, although repugnant, institution. There was no serious attempt to make it unconstitutional through the amendment process. In fact, many of the abolitionist wished for southern secession so that the United States, or at least the non-slave states, would no longer have a part in an immoral practice. I would agree with you that the amendment process is the proper process for adding or taking away the power of the federal government.
I am not trying to fight the Civil War, but rather, I am trying to lay out the basis for the next one. The storm is coming and people need decide who they are and what they believe in. I love the United States, but the government is not the United States, and this government is corrupt and rotten. Government is simply an institution, and when corrupted it is a danger to the people. I am much more interested in where people will stand today than I am in where they would have stood 150 years ago, but by examining the notions people have of the past you can get some insight as to where they will stand today.