A Supreme Court opinion is a mixture of law, fact, and interpretation.  By the time cases reach the Supreme Court, they amass a detailed record from the lower court(s) (except for the very few instances of original actions) and a large number of appellate filings.  The case with the most amicus briefs on the merits this Term, Whole Woman’s Health v. Hellerstedt, for instance, had 79 such filings.  These briefs, generally in support of one party, share information, statistics, and policy opinions with the Court.  The Court has to prioritize how it uses this information both in deciding on case outcomes and on decision language.

One way that I have assessed the impact of these filings in the past is through pairwise comparison of the text of each opinion with each brief.  This type of analysis is feasible with open-source software such as WCopyfind which is designed to locate plagiarism through the dyadic comparisons of texts.  For this post I compared opinions in every orally argued case with a signed opinion this Term with each brief filed in the case.

WCopyfind has several parameters that the user sets which affect the output.  The parameters with the greatest effect on the output have to do with the phrase length for the program to identify, and accuracy of the overlapping language.  I used the same settings in this post that I used in previous papers with this methodology.  The program was set to pick up phrases that were at least six words in length.  Five letter overlapping phrases would, therefore, not register.  The minimum accuracy was 80%.  This allows for slight deviations between the language of the two phrases so that each six-word overlapping phrase between brief and opinion must share at least 80% of the exact same language.

While in a previous paper, I show that opinions almost definitively lifted chunks (sometimes quite large chunks) of original language from briefs, there is little evidence of this practice in the Rehnquist or Roberts Courts.  Instead the overlapping language now tends to show when a brief was likely a helpful resource for opinion construction by conveying facts or law suitable for the opinion (e.g. this post does not contain revelations of a opinions plagiarizing large amounts of language from a briefs).  Most of the overlapping language is now found in shared citations and quotations or assertions of fact from the court of first impression that become part of the record .

WCopyfind provides output in terms of the percent of overlapping language between two documents and number of overlapping words.  The percentage of an opinion that overlaps with a brief is something that can be compared across each brief-opinion relationship and between cases.  This is the main unit of interest in this post.

Looking across the entire Term, there were 1,252 pairwise comparisons of briefs and opinions (I only focused on the relationships between filings and majority opinions but are additional combinations that can be formed by using separate opinions).  The majority of the briefs tended to share very little language (0-1%) with the opinions.  There were 36 instances of briefs that shared at least 10% of an opinion’s language.  The top 10 overlapping relationships by percentage of opinion shared with a brief range from 15% to 22% of the opinion.

Here are the relationships from this Term with the greatest percentage of an opinion’s language shared with a brief from ten to one.

• Lockhart v. United States opinion and Respondent’s (U.S.) Merits Brief (15%)
• Halo Electronics, Inc. v. Pulse Electronics, Inc. opinion and United States’ Amicus Brief (15%)
• Shapiro v. McManus opinion and Petition for Writ of Certiorari (16%)
• Nichols v. United States opinion and Petitioner’s Merits Brief (16%)
• Musacchio v. United States opinion and Respondent’s (U.S.) Merits Brief (16%)
• United States v. Bryant opinion and Petitioner’s (U.S.) Merits Brief (16%)
• OBB Personenverkehr AG v. Sachs opinion and Petitioner’s Merits Brief (17%)
• Nichols v. United States opinion and Respondent’s (U.S.) Merits Brief (17%)
• Shapiro v. McManus opinion and Petitioner’s Merits Brief (19%)
• Menominee Tribe of Wis. v. United States opinion and Respondent’s (U.S.) Merits Brief (22%)

The two main themes from this list are consistent across the majority of modern Supreme Court Terms.  First, party’s briefs on the merits (as opposed to amicus briefs) tend to share the most language with opinions.  These briefs tend to be holistic in their depictions of each case and are designed for such a utility.  Second, the Office of the Solicitor General tends to dominate in terms of language overlap.  Six of the ten highest instances of percentage overlaps for this Term are with briefs by the United States.  In addition, the only amicus brief on the list was filed by the United States in Halo Electronics.

To provide s few examples of this language overlap, here are some instances of overlap  between the United States’ Merits Brief and the Court’s opinion in Menominee based on the opinions actual language (page references are to the opinion):

• p. 9 “…absence of prejudice to the opposing party ‘is not an independent
  basis for invoking the doctrine [of equitable tolling] and sanctioning
  deviations from established procedures.’ Baldwin County Welcome Center v. Brown…Rather, the absence of prejudice is ‘a factor to be considered in determining whether the doctrine of equitable tolling should apply once a factor that might justify such tolling is identified.’ Ibid. (emphasis added).”
• p. 4 “‘do not, individually or collectively, amount to an extraordinary circumstance’ that could warrant”
• p. 6-7 “the circumstances that caused a litigant’s delay must have been beyond its control.”
• p. 8 “…upon an uncertain legal landscape, and impending deadlines. These circumstances are not ‘extraordinary.’”
• p. 8 “‘…for a litigant to be confronted with significant costs to litigation, limited financial resources”

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