In the case of Pennsylvania v. Union Gas Co., the U.S. Supreme Court ruled in 1988 that states could be sued in federal court under certain circumstances, despite their sovereign immunity as outlined by the Eleventh Amendment. The dispute arose when Pennsylvania sought to hold Union Gas responsible for costs associated with cleaning up a contaminated site under the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA). Union Gas argued that it was unconstitutional for them to be held liable because they were protected by state sovereignty laws. However, a majority of justices found that Congress had clearly intended to abrogate state sovereign immunity through CERCLA legislation and thus allowed Pennsylvania's suit against Union Gas to proceed.

In the dissenting opinion for Pennsylvania v. Union Gas Co., Justice Scalia, joined by Chief Justice Rehnquist and Justices O'Connor and Kennedy, argued that Congress does not have the authority to abrogate a state's Eleventh Amendment immunity under its Article I powers. The majority had held that such power was implied in the Interstate Commerce Clause of Article I; however, Scalia contended this interpretation was inconsistent with both historical understanding and precedent. He pointed out that at no point in history prior to 1988 had it been suggested or accepted that Congress could use its commerce power to subject nonconsenting states to private suits in federal court. Furthermore, he noted previous cases where similar attempts were rejected as unconstitutional extensions of congressional authority over states' sovereign immunity rights.