The policy may be sound, but the argument presented is not. The author acknowledges that crime has fallen nationwide, not just in San Francisco, but then presents as supporting evidence a comparison between SF and similarly-sized cities in the US. There is no city in America comparable to San Francisco. In recent years, SF has witnessed two huge tech booms, skyrocketing real estate value, and an influx of funding for public resources practically unrivaled among similarly small cities (because they refuse to construct new buildings). So SF is really not a good city to use as a model "sanctuary city" for comparison.

Let's talk instead about conflating factors.

- Liberal policies towards immigrants may be more popular in wealthier "coastal liberal elite"-type cities with highly educated constituents (like San Francisco).

- Cities that have high crime rates are probably more hostile to their immigrant communities, especially if those crime rates are related to drug/gang violence. In cities bordering the US/Mexico border, drug trafficking from Mexico is a major source of violent crime. US-born residents may associate their migrant neighbors with the drug trade and be less hospitable as a result.

I don't disagree with sanctuary cities, but the evidence presented in this article is so thin. I'm no more confident in my support of the policy than before I read it.