Adidas Promotional Retail Operations, Inc., Sports Chalet, and Offside Soccer (Adidas) are California retailers that sell athletic shoes made from the hides of the red kangaroo, the eastern grey kangaroo, and the western grey kangaroo. Viva! International Voice for Animals, an international nonprofit organization devoted to protecting animals, sued Adidas for violating California Penal Code Section 653o, which was enacted to prevent the extinction of species that the California legislature deems threatened and provides in relevant part: “It is unlawful to import into this state for commercial purposes, to possess with intent to sell, or to sell within the state, the dead body, or any part thereof, of any . . . kangaroo.”

The Federal Endangered Species Act of 1973 (ESA) was enacted to halt and reverse the trend toward species extinction. Section 6(f) of the Act states: Any state law.. which applies with respect to the importation or exportation of, or interstate or foreign commerce in, endangered species or threatened species is void to the extent that it may . . . effectively (1) permit what is prohibited by this Act or by anyregulation which implements this chapter, or (2) prohibit what is authorized pursuant to an exemption or permit provided for in this Act or in any regulation which implements this Act.

The ESA also includes a saving provision that states that the Act should not be construed to void any more restrictive state law.

During the twentieth century, a commercial market developed in Australia for kangaroo hides and meat. By the early 1970s, the kangaroo population had dropped to the point that the Australian state and federal governments instituted protective measures, including a ban on exports and species-specific quotas on the killing of kangaroos for commercial use.

In 1974, the U.S. Fish and Wildlife Service listed the red, eastern grey, and western grey kangaroos as threatened species under the ESA, which carries a prohibition on importation subject to exemptions and permits issued under the ESA. The Fish and Wildlife Service subsequently banned commercial import of these species until the Australian states harvesting them could assure the United States that their taking would not be detrimental to their survival. In 1981, the Service issued a special final rule lifting the ban on commercial import of these species. In 1995, the Service removed the three kangaroo species from the ESA’s list of endangered or threatened species on the basis of their successful recovery. Since the three species have been deleted under the ESA, their import into the United States is not prohibited by federal law.

In its defense, Adidas argued that California Penal Code Section 653o was preempted by the Endangered Species Act because the California law undermined federal actions taken under the ESA to influence the Australian state and federal governments to preserve threatened kangaroo species. How will Adidas support this argument? What arguments will Viva! Make in support of Penal Code Section 653o? Which party will prevail? [Viva! International Voice for Animals v. Adidas Promotional Retail Operations, Inc., 162 P.3d 569 (2007).]