Regulatory Takings Or Eminent Domain?

"On Election Day, voters in Arizona, California, Idaho, and Washington will face statewide ballot initiatives that would require taxpayers to pay landowners if a zoning rule or environmental law reduces the speculative value of their property. In some places, if a government couldn't pay, it would have to waive rules that limit what, or where, a landowner may build. These "regulatory takings" initiatives are styled after a controversial initiative, Measure 37, that Oregon voters approved in 2004 -- but this time, supporters have a new weapon in their arsenal."

Proponents of these initiatives are pushing them as defense against eminent domain, but this article from Grist outlines the difference between eminent domain and the real purpose of the initiatives, which is to limit 'regulatory takings'.