Say what you will about the likelihood of “slippery slopes” — and I’ve said more than most people — but it’s hard to categorically deny the possibility when the supporters of legislation are touting the possibility as a positive feature. From Nancy Pelosi, quoted by Ezra Klein (The Washington Post):
My biggest fight has been between those who wanted to do something incremental and those who wanted to do something comprehensive …. We won that fight, and once we kick through this door, there’ll be more legislation to follow.
Given this, it makes sense that one should decide whether to support or oppose this proposal not just based on its own terms, but on the likely shape of the “more legislation” that will be enabled by the proposal’s enactment.
Some may see this is a trivial point, because of course there’s a risk of slippage (i.e., a risk that the first step will increase the likelihood of future, more ambitious steps), and the real questions are figuring out how much that risk is, what the value of the first step is, and what the likely harm (if any) of the future steps will be. If that’s you, then I’m glad to hear it, since the goal of my work on slippery slopes has been to establish that very conclusion, and to suggest a framework for thinking about these questions.
But I’ve talked a lot about slippery slopes, often to quite sophisticated audiences, and I’ve often read and heard arguments that simply deny the legitimacy or utility of considering such slippery slope risks. I hope that hearing from advocates such as Nancy Pelosi will lead some people to recognize that slippery slope consequences are worth thinking about. If advocates of a proposal say “if you enact our proposal A, this will increase the likelihood of our future proposals B,” it seems to me quite reasonable for others to think hard about this possibility in deciding whether to go along with A.
For shorter versions of my long slippery slope paper, see this 54-page abridgment and this 10-page adaptation by Prof. Ward Farnsworth.