Sotomayor, J., dissenting
States,” the Court explained that “such obstruction can only arise when justice is being administered.” Id., at 207. “Unless that fact exists, the statutory offense cannot be committed.” Ibid. The Court thus tied obstruction of justice under §5399 to “the pendency of proceedings in the United States court, or the progress of the administration of justice therein.” Id., at 205.
Section 5399 is the predecessor of the modern omnibus or catchall obstruction of justice clause, which is codified at 18 U. S. C. §1503, and which prohibits endeavoring “to influence, obstruct, or impede, the due administration of justice.” In recognition of this through line, this Court held, just a year before the enactment of §1101(a)(43)(S), that “a person lacking knowledge of a pending proceeding” cannot be convicted under §1503. United States v. Aguilar, 515 U. S. 593, 599 (1995) (citing Pettibone, 148 U. S., at 207). Underscoring this point in his partial concurrence, Justice Scalia explained that “an endeavor to obstruct proceedings that did not exist would not violate the statute” because “obstruction can only arise when justice is being administered.” 515 U. S., at 610, n. 1 (alteration and internal quotation marks omitted).
Congress was aware of this settled interpretation of §1503 when it added “obstruction of justice” to the INA’s list of aggravated felonies. See Guerrero-Lasprilla v. Barr, 589 U. S. ___, ___ (2020) (slip op., at 10) (“We normally assume that Congress is aware of relevant judicial precedent when it enacts a new statute” (internal quotation marks omitted)). In fact, by 1996 Congress had already demonstrated that “relating to obstruction of justice” was understood to capture §1503. Enacted in 1970, the Racketeer Influenced and Corrupt Organizations Act (RICO) specifically lists as a predicate offense “section 1503 (relating to obstruction of justice).” 18 U. S. C. §1961(1). Moreover, this language, just like the language at §1101(a)(43)(S), serves the purpose of identifying one of a long list of underlying offenses to
