The U.S. Supreme Court's decision on Arizona's immigration law indicates that "a majority of the court accepts the broad powers of the federal government," says constitutional law expert Robert Schapiro, dean of Emory University School of Law. "Although the court did allow one important provision of the law to take effect, the majority focused on the potential disruption of federal policy."
"I see a conflict on the court between two positions advanced by the more conservative Justices," adds Schapiro, a former clerk for retired Justice John Paul Stevens.
"One position recognizes the evolving power of the federal government and the need to prevent states from interfering with federal authority," he says. "We see that by the fact that Chief Justice Roberts joined the majority opinion written by Justice Kennedy essentially recognizing the evolution of federal power in immigration law and concerned about the potential impact of state laws on foreign policy."
By contrast, says Schapiro, dissenters Justice Scalia, Justice Alito and Justice Thomas "emphasize a more originalist perspective, looking more historically at the role of the states and less at the evolution of national power in recent times."
While the decision in Arizona v. United States may not be a watershed moment for defining federal power, "it's an additional sign that Justice Kennedy and Chief Justice Roberts are not interested in a return to a much earlier vision of broad state power and limited national power," Schapiro says.
How far the court will go in defining the limits of federal power may be further tested later this week in the long awaited ruling on the Affordable Care Act.
Even if the court strikes down the individual mandate portion of the law requiring individuals to purchase health insurance, it's possible that that portion of the opinion "would not fundamentally rewrite the limits of federal and state power," says Schapiro.
What could be more telling is what the court says, if anything, about the expansion of Medicaid. The main way the federal government as a practical matter has expanded its influence, says Schapiro, is through its spending power, its ability to levy broad taxes, then give money to states on the condition that the states contribute money or effort toward advancing federal priorities. "That's been an extremely significant way for the federal government to have its policies implemented," he says.
"There's a chance, depending on what the court says about Medicaid expansion," says Schapiro, "that there could be a significant limitation on the power of the federal government."