But I don't think I use the term slippery slope in the same way the Wikipedia entry uses it. I don't think in politics you can ever say something like 'A will inevitably lead to Z.' I think it's different to say enacting A will make it more probable for B to occur, and that B makes C conceivable, where it might not have been with just A (or pre-A). Perhaps through these mechanisms from Eugene Volokh, summarized in Wikipedia for the gun regulation-confiscation example:
- Cost-lowering: Once all gun-owners have registered their firearms, the government will know exactly from whom to confiscate them.
- Legal rule combination: Previously the government might need to search every house to confiscate guns, and such a search would violate the Fourth Amendment to the United States Constitution. Registration would eliminate that problem.
- Attitude altering: People may begin to think of gun ownership as a privilege rather than a right, and thus regard gun confiscation less seriously.
- Small change tolerance, colloquially referred to as the "boiling frog": People may ignore gun registration because it constitutes just a small change, but when combined with other small changes, it could lead to the equivalent of confiscation.
- Political power: The hassle of registration may reduce the number of gun owners, and thus the political power of the gun-ownership bloc.
- Political momentum: Once the government has passed this gun law it becomes easier to pass other gun laws, including laws like confiscation.
There is no inevitability, since there's push-back by interested parties at every step, including push-back because of perceived slippery slopes. The gun example is a great example of just how non-inevitable slippery slopes can be.
In the strong sense of A inevitably leading to Z via the rest of the alphabet, slippery slope arguments are fallacious, but in this weak sense of expanding the political adjacent possible, slippery slope arguments and descriptions are valid. I thought to write this post after reading this essay (hat tip: Offsetting Behaviour) on John Banzhaf's rhetorical history. Banzhaf founded Action on Smoking and Health in 1968 and has been campaigning against smoking ever since. For example, in the early years of his career he clearly states support for smoking sections in public places, suggesting they're a reasonable compromise; but after smoking sections became universal he switched rhetoric, claiming smoking sections are useless since smoke drifts. The point isn't whether or not any of that is true; rather, it's the shifting rhetoric toward Policy C (banning smoking in public places) upon successful implementation of Policy B (establishing precedent for regulating where people can smoke by requiring smoking sections in public places). No one could have seriously argued for C from the beginning; B made C more probable.
Maybe by fuzzying up the concept of slippery slopes like this I'm voiding the phrase of all utility? I'm just using sloppy language for political workings? That is, if the polity can debate each point in the alleged slippery slope, you gain nothing by describing it as a slippery slope. Well, it's possible. I could talk about thresholds and hysteresis in politics, but then I'd just be throwing analogies after one another.
Conjecture: Liberals are more dismissive of slippery slope arguments than conservatives or libertarians. I would guess conservatives, in their quest to stand astride history yelling Stop!, find rather more use for slippery slopes than liberals. Certainly the slippery slopes that come to my mind most readily are conservative: gun regulation leads to gun confiscation, interracial marriage will lead to gay marriage will lead to dogs marrying cats, and health care reform leading to full nationalization of the health care industry.