In the fallacy thread, Scuzzaman has raised the issue of the slippery slope argument, which he argues is not necessarily fallacious. Let’s pause for a vid (without necessarily endorsing all that is said, this is food for thought):
Benjamin McLean here connects the issue to the principle of induction and so also to the post-Hume challenge to inductive reasoning. In short, a slippery slope argument is an inductive causal inference from present and past experiences, trends and dynamics to a possible future, inviting us to turn away before it is too late. As in:

When we cast the argument in this form, we can then see some of the force in SM’s point:
[SM, 77:] The OP [on fallacies] is deficient in reference to the Slippery Slope argument.
Not even the people making the argument 50 years ago would have given credence to legislatures forcing schools to let boys dress as girls and therefore – due to their stated opinion in opposition to their plain biology – be allowed entry to the girls bathroom, i.e. they had no possible clue as to the probabilities involved and nor in principle could they have.
Here in Germany several years ago the State decided that Germany should join the rest of the EU in explicitly banning sex with animals (although one should note, not as inherently deranged behaviour but as an affront to the rights of the animal). Announcement of this intention was followed by a public protest by over 200 literal “animal lovers” and their animals, claiming the contrary right to their previously legal practice.
Nobody ever made the argument based on the probability of Step 10 occurring in the context of the culture and mores at the time of Step 1. But the Overton Window is merely another description of the Slippery Slope: it describes not only the fact that certain subjects, facts, and opinions are officially forbidden or mandatory, but also that these categories are not only malleable but are actively manipulated over time in order to degrade public opposition to the managerial classes’ excesses.
We have overwhelming warrant from history to presume, a priori of any particular current demonstration, that no political action is ever solely what it appears and that long-term agendas inimical to our collective and several interests are perpetually being advanced. The “Boiling the Frog” illustration is also merely another version of the Slippery Slope argument. They all three (Slippery, Overton, and Frog) exist as common wisdom because the phenomenon they describe IS so common as to be inescapable.
Are misapplications of the argument possible?
Well, duh.
That doesn’t make the argument a fallacy, or else all forms of argument are fallacious.
The obvious issue here is, is there a ratchet effect that tends to strengthen and accelerate a damaging trend? If that obtains, it can be harder and harder to stop a slide down the slope, even if signs of a ruinous result are increasingly evident.
That is, the cogency of a slippery slope argument depends on the strength of its ratcheting mechanism. If one is present and is arguably strong, “a stitch in time saves nine.” However, as the change challenge diagram illustrates, it is often very hard to build a critical mass of support to act in good time, and as Machiavelli long since observed, by the time the course of a destructive policy disorder is manifest to all, it is too late to cure.
(And yes, that is a key part of why democratic forms of government are inherently unstable and must be stabilised through cultural forces that build a critical mass of support for prudence. Where, also, business as usual is so precisely because it is what those who hold the balance of power want or will tolerate.)
This brings up the Overton Window issue:

Here, we see an illustration of how power balances and support for policy can move across time. Where, proverbially, elections are won in the middle, through the swinging vote (and sometimes through disaffection of supporters who do not support one who would naturally be their candidate save for some issue or scandal X). In that context there are two BATNA points, where a critical mass will reject a proposal beyond that threshold, swinging the balance of voters or policy makers decisively against the relevant perceived radical faction.
So, the issue is, is there a ratchet on the BATNA, pushing it to one side or the other? If so, how strong is it and where will it lead? Can it be broken, swinging the trend the other way?
These may be quite difficult questions to answer, but they clearly show that the real fallacy is the trend to use “slippery slope” as a thought-stopping, dismissive talking point.
Especially, when the lessons of sound history (not victory propaganda) were bought with blood and tears; so those who neglect, reject or dismiss them doom themselves to pay the same coin over and over and over again. END
PS: It is worth a pause to again draw attention to the reason why constitutional democratic government is inherently unstable and must be stabilised by the consistent action of a prudent, well informed, vigilant public:
