I wasn't sure where to put this, as it is a question pertaining to logic, but not mathematical logic per ce. I don't understand why the slippery slope argument is considered a fallacy, especially in a political context. While it is obviously incorrect to say that some action inevitably leads to a consequence by means of a slippery slope, it does not seem incorrect to say that it can make such a consequence more likely. Incrementalism (the idea that the public will not tolerate large, sweeping changes but that smaller, incremental changes can lead to the same result without as much opposition) is an idea that has historically been used by political leaders, such as Ceasar Augustus. I was thinking about this in the context of the senator who recently proposed the biometric ID card as part ofd the immigration reform bill. He basically said that the public was ready for this because in today's society we are constantly made to show ID. It seems that if such a rule was passed (this bill specifically creates a biometric ID card that would be required as verification of empolyment elligibility) it does in fact make anothe rule (such as hypothetically that such cards could be a requirment for voting) more likely. This post is not about biometric ID, but about the notion of the slippery slope. It seems logical that in a case where a progressive series of changes have been tending in a general direction, but no individual change seems unreasonable given the current state of things, there becomes a necessity of "drawing the line" somewhere by pointing out the slippery slope. I understand the difference between "inevitably leads to" and "makes more likely" but can someone explain why this is considered a logical fallacy?