The context of this discussion is deterrence of drug dealing in a city with
a legitimate substance abuse mortality emergency--in other words, where any marginal deterrence effect, such as slightly reduced drug availability, might directly translate to double-digit saved lives over the course of a single year. And one aspect of this issue (apropos the injunction rejected by the appellate court) is that the city has an elected DA who is ideologically opposed to any incarceration for non-violent offenses. (And to be clear, in his view drug dealing is non-violent, even when carrying a gun and creating an implicit threat of violence--which I don't necessarily find unfair, just trying to be clear that few if any arrested drug dealers face the threat of incarceration under Boudin as a prosecutorial policy matter.) While I think politics has begun to corrupt Boudin, I actually think he's an atypically sincere, honest (though trending down--politics
corrupts), principled person, and I agree in principle with
most of his policies. However, because there's effectively no incarceration for this class of offense, when drug dealers are arrested they're typically back out on the same corner in a couple days. Over and over and over again--not hyperbole. (This is part of the reason why SF police have mostly stopped arresting dealers. Just part, though--I'm not apologizing for the SF police departments larger diligence issues.) Note that because Boudin is a principled person in this regard, he laudably refuses to abuse pretrial detainment when he has no intention to seek incarceration, much to the frustration of a system that sadly relied so heavily on that abuse before.

The commonly held belief is that drug dealers, especially street-level, are basically fungible and quickly replaced. There's clearly truth to that. But now this belief is being tested to the extreme. It's also true, as any student of economics would tell you, that there's always some marginal effect to a policy, even a crappy one; the real question is the magnitude of the effect. (And to avoid muddying the equity waters, I'm ignoring the fact that the threat of incarceration provides leverage when trying to get street-level dealers to flip; FWIW, I do agree coerced plea deals is a legitimate problem, but notably also an issue where scope and severity matter, not simply nominal existence of an incarceration threat.) Usually in public policy debates we stick to qualitative aspects rather than quantitative, justifiably or not. But Boudin's radical anti-incarceration policies has made SF a fascinating experiment where the precise magnitude (whether as deterrence or simply as removing a criminal temporarily from the population) could make a signifiant difference; it's the only relevant question left, at least in the short-medium term.

The present situation in the city is a difficult one for Boudin, politically speaking. It's becoming clear (at least to me) that Boudin is hiding behind the ambiguity in incarceration statistics. I also think this must be
willful, because Boudin is also committed to shorter incarceration sentences for violent crimes, so he clearly understands there's a meaningful,
consequential distinction between some jail time and none. (FWIW, I support a lighter sentencing policy for violent offenses, and if this were his only
policy I'd be glad someone with the backbone--or at least intransigence--of Boudin were in office. Most other viable SF district attorney candidates would have a similar policy, at least nominally, but might not have the wherewithal to follow through to the same extent.)

Almost everyone agrees that incarceration rates (i.e. per capita rates) are
too high, at least at a national level. (I haven't found good per capita
incarceration rates for San Francisco specifically, but almost certainly
it's substantially below national levels, and likely has been for awhile
given San Francisco has been at the forefront of criminal justice reform
decades before Boudin. But let's just say they're still unjustifiably high.) As long as people don't or can't distinguish between no
jail time vs lesser jail time, Boudin can sustain greater support than he
could otherwise. Most voters are strongly committed to improved criminal
justice equity, even when it comes with real negative costs. Boudin has been able to position his [extreme] policies as a choice between pursuing or rejecting
meaningful reform, full stop. But if the prospect of achieving all or most of that
improved equity without some of the extreme and deadly costs currently
demonstrated in SF, then what remnants of local support Boudin enjoys would
quickly crumble. (National support for Boudin would likely be sustained as
after holding Boudin up as an archetype, national reform advocates are afraid a Boudin loss would benefit their opponents. For the
same reason they're also afraid of the consequences of allowing any debate
over this distinction in metrics, period. In America that's why we can't have nice
things--so much, including acceptable policy alternatives on an increase array of policy areas, is radically polarized.)

I think it's important to make these distinctions. I think they matter. And
in SF, they might even matter to the sum of demonstrably, significantly
reduced deaths. But I admit that's not at all guaranteed. The marginal effect of pursuing even short incarceration for repeat offending street dealers might indeed be de minimis--either intrinsically or simply dwarfed by the
negative effects of the city's broader so-called "harm reduction" strategy wrt drug use.