Say more. I don't have a strong opinion one way or the other.
His beef is that local authorities are ignoring ICE detainer requests, and then cites to 8 USC 1373 as if that makes it illegal for local authorities to ignore such requests (it doesn’t) and then nonetheless says that his interpretation of 8 USC 1373 doesn’t run afoul of the anti-commandeering rule (which it would, if his interpretation were valid).
Also, a quick google indicates that, to the extent that 8 USC 1373 is interpreted to impose affirmative obligations on state or local authorities, it is probably unconstitutional.
I’m not saying that I think state and local officials should be able to thumb their noses at federal immigration law, but I am saying that the statute he cites to doesn’t stop them from doing so.
I would also say that the anti-commandeering rule should probably be revisited, at least to the extent that, as currently crafted, it would prevent the federal government from legally requiring local officials to keep people in custody if they receive a detainer request from ICE. Without the power to compel local officials to keep someone like that in custody, it becomes extremely difficult for the federal government to enforce immigration law with respect to immigrants who break other laws, and I have serious doubts that the Framers intended the gap between federal and state to be quite so hermetic.