There was a show a few years back on PBS (I think) about the Revolutionary War and the development of the United States and they had actors reading quotes by various people of the day. What was really curious was the number of "If you do X, then Y will eventually happen" quotes that have since turned out to be quite true with respect to the Constitution.
Those were "slippery slope" arguments which many people here on FR absolutely refuse to believe would happen to an issue they are advocating regardless of past history.