Any law, rule, or regulation that attempts to regulate a right is necessarily void; such regulation attempts to convert a right into a permission. Our natural right to defend ourselves incorporates out right to carry the means to do so and includes firearms.

Additionally every search performed with a warrant is presumed unlawful. The need for searches, presumably to keep out guns, would require warrants. Such searches would be for collecting evidence to be used in a criminal proceeding, making them outside the scope of any recognized exemption to the warrant requirement. And it is not enough that the building is a public building to circumvent the 4th amendment. Specific facts relevant to the location that one wishes to search must be shown and this is lacking. Luckily, our forefathers understood and meant the 4th amendment not to incorporate a "feel safe" meaning to the 4th amendment; to search someone is a very serious matter and I see no reason to search people mearly because they wish to attend a public meeting or meet with a public official. 

If anyone is that scared of shadows I suggest that they seek employment outside of the public sector. Don't try to tread on me.