A recently published article on foreign law citations in US cases is up on SSRN. Kenneth Anderson argues that the use of international law in US cases goes against the political underpinnings on which our entire political system is based. His primary argument is that foreign law is derived from a different system of government, which in the case of Western Europe eschewed popular sovereignty because it was equated with populism and the cause of so much evil. Our system is predicated on the will of people, so citations from foreign courts are interpretations of laws that are derived from distinctly different origins.
Richard Posner similarly opposes citing foreign law, in part because the problem "with citing foreign decisions in U.S. courts is that they emerge from a complex socio-historico-politico-institutional background of which our judges, I respectfully suggest, are almost entirely ignorant."
Perhaps a slightly different point which focuses on the ability of the justices to properly understand the interpretations they are citing rather than the divergent nature of the interpretation vis-a-vis our legal system. But both arguments lead to same conclusion: foreign law cannot properly be applied in our legal system because it is different. Yes, the issues facing those countries very often are part and parcel of our political and legal disputes. But the solutions they propose cannot be applied because the structural dynamics are sufficiently distinct in our country to render the conclusions of foreign judges useless. Each country has its system of law, which is based on the structure of the society from which it is derived. It's apples and oranges.