Opinion of the Court
proceeding be pending. See generally ALI, Model Penal Code §240.0(4), p. 3 (1980) (“ ‘official proceeding[s]’ ” include those which “may be heard”). For witness tampering, for example, the Model Penal Code focuses on an actor’s intent to tamper with a witness, not whether an investigation or proceeding is pending. See id., §241.6, Comment 2, at 166–167 (“What is important is not that the actor believe that an official proceeding or investigation will begin within a certain span of time but rather that he recognize that his conduct threatens obstruction of justice”).
That extensive body of authority—dictionaries, federal laws, state laws, and the Model Penal Code—reflects common sense. Individuals can obstruct the process of justice even when an investigation or proceeding is not pending. For example, a murderer may threaten to kill a witness if the witness reports information to the police. Such an act is no less obstructive merely because the government has yet to catch on and begin an investigation. As the Solicitor General persuasively states, one can obstruct the wheels of justice even before the wheels have begun to move; indeed, obstruction of justice is often “most effective” when it prevents “an investigation or proceeding from commencing in the first place.” Brief for Attorney General 15.
Importantly, if an offense “relating to obstruction of justice” under §1101(a)(43)(S) required that an investigation or proceeding be pending, then many common obstruction offenses would not qualify as aggravated felonies under that provision. We decline to interpret §1101(a)(43)(S) to exclude numerous heartland obstruction offenses. “We should not lightly conclude that Congress enacted a self-defeating statute.” Quarles v. United States, 587 U. S. ___, ___ (2019) (slip op., at 8); see also, e.g., Stokeling v. United States, 586 U. S. ___, ___–___ (2019) (slip op., at 7–8); Esquivel-Quintana, 581 U. S., at 395; Voisine v. United States, 579 U. S. 686, 695–696 (2016).
