The article and the HN comments linked are about attempts by private publishers to lay claim to state codes, not about their success in doing so. The blog article concluded that they would be completely unsuccessful as to copyrighting the text itself and generally cites case law supporting this proposition. (See the blog for the cites.)

As I stated before, the text of the state codes cannot be copyrighted as a basic rule of American law.

Other aspects can be copyrighted, and this is where copyright gets tricky. The formatting (i.e., presentation) of a state code can be copyrighted, as can analysis of the code (b/c that is a distinct work), and the particular database selection can also be copyrighted within reason (meaning the particular choice of items stored and the relationships between them, so long as such choice and relationships are not purely functional).