The Court decided a number of important cases addressing the relationship between states and the Federal government under the Constitution.
In Virginia Office for Protection and Advocacy v. Stewart (09-529), the Court held that principles of state sovereign immunity did not prevent Virginia's Office for Protection and Advocacy ("VOPA") from suing the State of Virginia in Federal court to enforce Federal law. Federal legislation had offered states money for implementing assistance programs for people with disabilities. Virginia had created VOPA as an independent agency pursuant to this legislation, and VOPA was seeking injunctive relief to compel the State to disclose documents pursuant to the Federal law. The majority held this to be permissible under Eleventh Amendment sovereign immunity principles. Chief Justice Roberts, joined by Justice Alito, dissented strongly, arguing that the majority's holding represents a dangerous intrusion into state sovereign immunity and will lead more state agencies to sue state officers in Federal court.
In Bond v. U.S. (09-1227), the Court held that a person indicted under a Federal statute has standing to challenge the statute on the Tenth Amendment grounds that, in enacting the statute, the Federal government invaded state powers under the Constitution. The question was whether individuals can assert states' rights under the Tenth Amendment, or whether this is something that is left to states. The Court held that an individual's right not to be jailed for an allegedly unconsitutional law does not belong to the states. "Federalism secures the freedom of the individual," and thus creates individual rights alongside state rights, according to the Court.
In three cases involving significant Federal legislation, conflicting state law and state law claims were held to be preempted. In AT&T Mobility LLC v. Concepcion (09-893), a divided Court held that the Federal Arbitration Act preempts a California law that rendered arbitration agreements unenforceable if they involved waiver of class-wide arbitration. In Bruesewitz v. Wyeth LLC (09-152), the Court held that the Federal National Childhood Vaccine Injury Act of 1986 preempts design defect claims brought under state law against vaccine manufacturers. And Pliva, Inc. v. Mensing (09-993, 09-1039, 09-1501) held that Federal drug regulations applicable to generic drug manufacturers preempt state tort law claims based on an alleged failure to provide adequate warning labels. Justices Sotomayor and Ginsburg dissented in all three of these cases; Justices Breyer and Kagan joined the dissents in the Concepcion and Mensing cases.
In Chamber of Commerce v. Whiting (09-115) a divided Court held that Arizona's controversial law penalizing the employment of illegal immigrants is not preempted by Federal immigration law. The majority reasoned that the Arizona statute doesn't conflict with Federal immigration law; dissenting Justices Breyer, Ginsburg, and Sotomayor disagreed.