Is there a legal leg to stand on on being able to vape indoors in the US? If so, could you please supply the link?
Absolutely. It is legal everywhere it isn't prohibited by specific law. Keep in mind that businesses can make their own rules regarding additional acts they don't allow in their establishment. So while it might not be illegal, it might be prohibited in the specific building you happen to be in.
The Virginia Department of Health announced that it considered use of electronic cigarettes to be smoking. The Virginia Attorney General disagreed: http://www.oag.state.va.us/OPINIONS/...-029-Peace.pdf
Thus, vaping is defintely legal in Virginia.
I believe that the only state specifically prohibiting indoor use is New Jersey. There are a few communities that have revised their clean air acts to specifically include e-cigarettes. The largest one that I know of is the city of Savannah, GA.
Those that have banned indoor use have done so out of fear. "It looks like smoke, so it must be dangerous." We have many tests that show nothing harmful in the vapor. See: CASAA.org
What makes smoke harmful is the tar, carbon monoxide, particulates, and thousands of chemicals created by the process of combustion. Nothing is set on fire and burned in an e-cigarette. Ergo, there is no smoke.