Heard this story on N.P.R. tonight while driving home: The Pennsylvania State House is considering legislation that would preempt local land use policies that restrict ‘hydrofracking’ within their jurisdictions. I think it would be fair to say that this proposal aims at the heart of US zoning’s basis for legitimacy.  That is, keeping industrial nuisances out of residential neighborhoods is the most basic premise for authorizing a zoning ordinance.  Historically, zoning was a direct response to the land-use chaos ensued from the Industrial Revolution.  Seriously: If the state won’t allow local governments to keep hydraulic fracturing out of residential neighborhoods, what business does it have authorizing them keep out apartment houses or barbershops?