Political rhetoric question/contest: "slippery slopes"

Due no doubt to the few years I spent producing political rhetoric and the many decades I have spent ingesting it, I'm obsessed with endlessly interested in the connection between the words we use about public life and the decisions we make and attitudes we hold. For instance, that's the point behind the "God bless America!" or "boiled frog" watch. These are cases where language actually takes the place of thought. Yes, I realize that I'm not the first person to have noticed this connection. Indeed in my GBA/frog campaigns I am remiss in not having quoted Rule #1 from the modern classic work on the misuse of language in political discourse:
"1. Never use a metaphor, simile, or other figure of speech which you are used to seeing in print."

Which leads to this open question, suggested by reader Webster Marquez:

"The health care debate (and, indeed, the debate around Obama's and Democrats' agenda) is filled with rhetoric about "slippery slopes." To wit: health care reform => government takeover => tsarist communism! Somehow!

"Can you find any examples of a slippery slope argument actually bearing out? A leads to B, which leads to C, all the way to Z?

"How is it that an argument that is considered a "classic informal fallacy" (per Wikipedia, but I remember this family of concepts from college philosophy) is given so much currency across the media and political spectrum?"


Although the finest and most famous example of pure slippery-slope rhetoric is Ronald Reagan's renowned 1961 broadcast about the risks of socialized medicine, it's worth noting that this reasoning can be applied from any part of the political spectrum.  Eg: Patriot Act => elimination of civil liberties => fascism in America. Just this morning I heard a representative of ACORN used the "criticism of us => return of McCarthyism" form of the argument. Similarly, most objections to the Obama Administration's decision to cancel European missile-defense plans concern not the Czech/Polish sites themselves but the "sign of weakness => encourage agressors => appeasement brings on Another Hitler" concept.  (Image from here.)

I know that for some people, Mr. Marquez's question is too easy to answer. If you think we already live in Fascist Amerika, or that it's been a one-way trip down the road to moral collapse since [Elvis Presley, the Miranda ruling, choose your starting point], real life is a living confirmation of slippery-slopeism. But as a de-politicized, purely analytical question, I wonder what the best real-world example of this phenomenon is. To be clear, we're talking about a situation where one step leads unavoidably to another -- in which people end up with Consequence Z, which they never would have chosen, purely because they took initial steps A and B. Almost as if they started down a slope, and began to slip, and then...    Nominations welcomed; results will be announced.