Ranking the Court’s Top Cases
In Federalist No. 78, Alexander Hamilton described the judiciary of the proposed U.S. government as the “least dangerous” of the three branches. Events of the past few years might have Hamilton reconsider his famous position, as the Supreme Court has consistently appeared in the press for controversial society- and government-shaping opinions.
Whole cottage industries dedicate themselves to finding the Greatest of All Time in virtually every endeavor, from NFL quarterbacks and NBA guards to fashion designers and artists. Academics have their own such lists, with annual examinations of the greatest presidents, economics policies, and, yes, Supreme Court holdings.
While we enjoy reading all the lists, the Supreme Court has a special place in our hearts. Inconspicuously positioned off the National Mall, the Court often operates in the background of the frantic D.C. political hullabaloo. But from the beginning of our constitutional republic, the high court has punched above its weight. Never afraid of reminding the country of its jurisdictional superpowers, the Court has given the last word on some of our most important national issues, from abortion rights to gay marriage to health care availability.
That is particularly evident in the world of environmental law, as the Supreme Curt sought to interpret the explosion of statutes passed in the 1970s and 1980s. Those cases largely still govern most of the environmental realm today. Guided by rules of statutory interpretation, and no shortage of policy persuasions, the Court directed the development of law and established both opportunities and setbacks along the winding road toward sustainability.
Many scholars have addressed the question of identifying the most significant of the Supreme Court’s environmental decisions. In a series of articles in the Environmental Forum, for instance, Professors J.B. Ruhl and James Salzman identified what they called “American Idols” by polling professionals in 2001, 2009, and 2019. Their results were presented in a chart of the most important 10 decisions. Interestingly, but perhaps unsurprisingly, the top result changed each time they conducted the poll. TVA v. Hill headed the chart in 2001, but Massachusetts v. EPA took the spotlight in 2009. Completely expectedly, Chevron v. NRDC stole the hearts of voters and swept the 2019 competition.
While we completely laud Professors Ruhl and Salzman for their fascinating polling data, their lists are a little bit like a beauty pageant, voting for the most likeable. We decided to flip in at least a flavor of objectivity, beginning with the premise that the most important decisions would be those that lower courts most relied on, as of (Month) 2024.
Our strategy at the start seemed simple enough—we intended to take each case and track its citing references using Westlaw and Lexis, to observe its life over time. We anticipated that cases with higher citing references would have a greater impact than cases with fewer citations. But we quickly encountered some challenges. Some cases, like Lujan v. Defenders of Wildlife, undoubtedly changed litigation strategy. Counsel would not advise wasting resources just to have a case thrown out for standing, but that would also mean numerous cases that could be never were. We also found that some cases were coopted by other fields of law—criminal, administrative, etc.—and therefore had ghost citations that had nothing to do with our core subject. Finally, several cases had tens of thousands of cites, enough to keep a team of dedicated research assistants busy for semester after semester. Slowly, our research methods changed. In the end, we settled on total citations, ghosts and all, divided by years since the decision dropped. That ratio would give the average citations per year—not unlike a Major League batting average.
Our final list is composed of those environmental cases which had the most significant impact on the law as judged by how many courts, Supreme or otherwise, employed them in decisions. We then simply ranked the decisions by that average to produce a top-10 list—our Heavy Hitters.
A brief note on some other methods we considered. Initially, we anticipated employing the headnotes feature on Westlaw and Lexis. We thought that filtering for only those cases which cited the environmental headnotes of the case would allow us to find cases that only sat within the environmental law space. This method had several critical flaws. For one, it relied on a surprisingly ineffective system. The headnotes themselves often both over- and under-include relevant citing sources. Certain environmental headnotes, like the cases themselves, were also adopted by other fields of law. Additionally, some critical environmental holdings, especially in older cases, either were incorrectly headnoted or lumped into other headnotes. As a result, the search programs would say these cases received only a handful of citations, even though this was simply not true.
Abandoning the headnotes, we considered keyword searches in the lists of citing references, but we ran into similar problems. Nonetheless, it is worth noting that, with some exceptions, our efforts to sort by headnote or keyword largely tracked the total citations. With the notable exceptions of Winter and Lujan, our Heaviest Hitters generally made the cut whether we used either methodology, though the list would change order somewhat. This generally makes sense, as the cases above (again excluding Winter and Lujan, as well as Chevron) tended not to stray too far from the environmental fold. But uncertainties in our results led us to keep the methodology and scope described above.
Our list shares a lot with the list composed by Professors Ruhl and Salzman. Winter, Lujan, Chevron, Massachusetts, Penn Central, Sierra Club v. Morton, UARG, and Whitman appear in both our lists. The one case that made our cut and not the Professors’ is Bestfoods.
This of course creates just a bit of confusion. After all, we based our results solely on citations, and the professors used qualitative methods to arrive at their conclusions. So what is with the overlap? The correct answer is the simplest: Important cases get cited more frequently.
Maybe a more important question is what cases that made the cut for the professors didn’t stick around on ours. Looking at the 2019 survey, Rapanos, TVA v. Hill, and Overton Park didn’t pull through. On our master list, TVA v. Hill came in 12th, with 37 cites a year, Rapanos placed 15th, with 26 cites a year, and Overton Park landed in 21st, with only 16 cites per year. These cases didn’t do too terribly, and if we had knocked out the Winter, Lujan, Chevron outliers for their ghost citations, TVA v. Hill would have kept its spot on the list.
At risk of sacrificing our quantitative impartiality, we do have our own views as to why these top 10 cases were cited so much. Environmental law often drives watershed changes in administrative law. The recent FDA v. All for Hippocratic Medicine case provides a good example. In that decision, the Supreme Court found the doctors challenging the abortion pill lacked Article III standing. The case relies heavily on Lujan, Summers v. Earth Island Institute, and other environmental cases not for their environmental implications, but their standing doctrines. As Hippocratic Medicine illustrates, some key environmental cases wear multiple hats. We call these cases “dual hatted,” meaning that they could be cited for both environmental and administrative law reasons.
Top Environmental Heavy Hitters, Raked by Average Citations Per Year
1 Winter v. NRDC (2008) is a National Environmental Policy Act case that primarily considers the impact of sonar on marine mammals—but it has had an outsized impact for its straightforward presentation of the standard of law on preliminary injunctions.
Total Cites 21,832; Average Per Year 1,365
2 Lujan v. Defenders of Wildlife (1992), a case about the Endangered Species Act, remains the quintessential case on standing. Justice Antonin Scalia wrote that the plaintiffs lacked standing under Article III of the Constitution, because they based their claims on speculative environmental harms rather than “actual or imminent invasion of a legally protected interest.” TC 35,308; APY 1,103
3 Chevron v. NRDC (1984), which just entered oblivion, was not—despite what many commentators have suggested—the most cited case of all time, and the Supreme Court has not cited it since 2016, according to Loper Bright, the case that supplants it. But it still made it into the top echelon. TC 18,640; APY 466
4 Massachusetts v. EPA (2007) is, of course, the ultimate environmental decision. However, it is also the case to be cited by a state seeking standing, by giving states “special solicitude” to “protect[] [their] quasi-sovereign interests.” TC 1,302: APY 77
5 United States v. Bestfoods (1998) is one of the dual-hatted cases. It is first and foremost a Superfund decision on the liability of parent’s corporations. However, its corporate law discussion is relevant beyond the 1980 Comprehensive Environmental Response, Compensation, and Liability Act into other areas of law. TC 1,797; APY 69 (tie)
6 Penn Central v. City of New York (1978) said a city can restrict alteration and development of historical sites without causing a taking. This landmark decision established the now famous Penn Central test for compensation for a regulatory taking with three factors: “economic impact of the regulation on the claimant”; the extent to which the regulation interferes with “distinct investment-backed expectations”; and the character of the government action. TC: 3,171; APY 69 (tie)
7 Sierra Club v. Morton (1972) held that the club lacked standing to sue under the Administrative Procedure Act because it failed to show that any of its members had suffered or would suffer injury as a result of the defendants’ actions. Justice Potter Stewart wrote the opinion for the 4-3 majority, in which the Court held that, in order to have standing to sue under the APA, the plaintiffs must demonstrate they had directly suffered an injury as a result of the actions that led to the suit. TC 3,193; APY 61
8 Sackett v. EPA (2023), a new decision, made the list because it received so many citations within the first year after releasing. That is due, in no small way, to how extensive the controversy on “waters of the United States” under the jurisdiction of the Clean Water Act is right now. However, because Sackett now determines CWA jurisdiction, it is likely to remain an often-cited decision. TC 51: APY 51
9 UARG v. EPA (2014). Justice Scalia delivered the opinion of the court considering the regulation of greenhouse gases from stationary sources under the Clean Air Act, holding that EPA reasonably interpreted the act to require sources that would need permits based on their emission of conventional pollutants to comply with Best Achievable Control Technology but lacked authority to “tailor” the act’s numerical thresholds to accommodate its greenhouse-gas-inclusive interpretation of the permitting triggers. TC 501; APY 50 (tie)
9 Whitman v. American Trucking (2001), another dual-hatted decision, and also written by Justice Scalia, held that the Clean Air Act properly delegated legislative power to EPA, and that the agency could not consider implementation costs in setting primary and secondary National Ambient Air Quality Standards. The Court also found EPA’s implementation of the NAAQS was unreasonable. This case, however, is most often cited for its ruling on the allegation of illegal delegation of legislative authority and the inability to consider costs in this instance. TC 1,151; APY 50 (tie)
TESTIMONY In the box score on page 49, the authors present the heavy hitters—the most influential environmental decisions by the nine justices, ranked by how often courts cited the cases in later holdings.