even though the Ninth Circuit panel found that the right to bear arms generally applies to state and local governments:

(1) The ordinance that barred possession of guns on county property did not materially burden people's ability to defend themselves on private property, especially in the home.

(2) The government generally has the power to restrict the exercise of constitutional rights on government property, citing the Court's abortion rights cases. Probably the strongest such case on the county's side, which the panel didn't cite, was Webster v. Reproductive Health Servs. (1989), which upheld a state law banning "the use of public employees and facilities [including any public institution, public facility, public equipment, or any physical asset owned, leased, or controlled by this state or any agency or political subdivisions thereof] for the performance or assistance of nontherapeutic abortions."

(3) Heller's suggestion that the government may ban "the carrying of firearms in sensitive places such as schools and government buildings" also applied to "the open, public spaces the County's Ordinance covers," including county parks and the fairgrounds. The panel suggests that "The Court listed schools and government buildings as examples, presumably because possessing firearms in such places risks harm to great numbers of defenseless people (e.g., children). Along the same lines, we notice that government buildings and schools are important to government functioning."

It's not clear exactly what test the panel was applying for deciding what constitutes a "sensitive place[]," especially since county parks and the fairgrounds are probably not as "important to government functioning" as are schools (running which has long been seen by American state constitutions as a core government function) and many government buildings. Is it that all "prohibiti[ons on] firearm possession on municipal property," including public streets and sidewalks — i.e., total carry bans, including in one's car or on one's person on the sidewalk — are constitutionally permissible? (Note that while the government generally has the right to restrict the exercise of many constitutional rights, including not just abortion rights but free speech rights, in many government buildings, it generally is substantially constrained by many provisions — such as the First and Fourth Amendments — on public streets and sidewalks.)

Would the "sensitive places" exception cover only prohibitions in places "where high numbers of people might congregate" (with the threshold perhaps higher than the number of people that would usually be present on a normal city sidewalk)? Would state and federal parks in the sense of Yosemite and the like, as opposed to small city and county parks, also qualify? What about people's apartments in public housing projects, which are "municipal property" but not themselves places where many people congregate?

For more on these questions, you might have a look at PDF pages 31-34, 85-89, and 72-80 of my forthcoming UCLA Law Review article on implementing the Second Amendment. I'm inclined to say that the panel's general analysis on this guns-on-public-property is considerably more cursory and less clear than it ought to be — though I'd also say that, for reason 1 noted above, coupled with aspects of reason 2, the ordinance would be clearly constitutional when applied to selling guns on government property, and displaying them for sale there.