i only know OSHA as the "dock nazis." i don't ever take on responsibilities i can avoid at sea because they're liable to slap fines on us for not wearing a life vest correctly.

I used to "do" OSHA. The OSHAct contains what's known as the "general duty" clause. It states that employers have a general duty to provide a "workplace free from recognized hazards." The idea is to take steps as required to "provide a safe and healthful workplace." The reasoning goes: guns in the workplace are a recognized hazard. Witness the various workplace shootings over the years. An employer can be viewed as complying with its general duty under the OSHAct to provide a workplace free from recognized hazards by bannings guns. The OSHAct contains preepmtion provisions, overruling state laws to the contrary. Thus, a state law that prevents an employer from ridding guns from its workplace is an obstruction and impediment to compliance with the OSHAct and is preempted.

I don't really buy that argument, but there it is. If I recall right, it worked in the Oklahoma case. Somebody check me on that, though.

Oh, and the constitutionality of OSHA was settled long ago.

I can also say that the taking by regulation is going to get them precisely nowhere. I had to research this one a couple years ago. Lots of folks have argued that for lots of regulations (mostly environmental regs) - almost entirely unsuccessfully. Your property must be rendered utterly and completely useless and valueless by a regulation for it to be an unconstitutional "taking." As long as you still have some use of your property and it retains some value, it has not been "taken." A law saying you can't ban guns in locked cars in your employee parking lot in no way rises to the level of a regulatory taking of your property. Some argue for a "partial" taking by regulation; i.e., you're owed compensation to the extent your property value or use was diminished. But again, those are tough cases and have not met with wide success.

The OSHA argument did work for them in the OK case, but as far as I know that has not yet reached the Appeals court. They will find a friendly judge and win in District court, then the fun will start.