Mr. Justice Frankfurter delivered the opinion of the Court.
Petitioner was convicted by a jury in the United States District Court for the Eastern District of Missouri on two counts. Count I charged a conspiracy to obstruct commerce by extorting money, and Count II charged the substantive offense of obstructing commerce by extortion, both crimes made punishable by the Hobbs Anti-Racketeering Act, 18 U.S.C. §1951. Petitioner was sentenced to consecutive terms of twelve years on each count, but the sentence on Count II was suspended and replaced with a five-year probation to commence at the expiration of his sentence under Count I. On appeal, the conviction was affirmed, 223 F.2d 171.
Petitioner thereafter sought a correction of his sentence, invoking Rule 35 of the Federal Rules of Criminal Procedure as well as 28 U.S.C. §2255. He claimed that the maximum penalty for obstructing interstate commerce under the Act by any means is twenty years and that Congress did not intend to subject individuals to two penalties. The District Court denied relief, holding that the Hobbs Act gave no indication of a departure from the usual rule that a conspiracy and the substantive crime which was its object may be cumulatively punished. … The Court of Appeals for the Eighth Circuit affirmed this judgment. ... Deeming the question raised by petitioner of sufficient importance, we brought the case here.
Under the early common law, a conspiracy - which constituted a misdemeanor - was said to merge with the completed felony which was its object. … This rule, however, was based upon significant procedural distinctions between misdemeanors and felonies. The defendant in a misdemeanor trial was entitled to counsel and a copy of the indictment; these advantages were unavailable on trial for a felony. … Therefore no conviction was permitted of a constituent misdemeanor upon an indictment for the felony. When the substantive crime was also a misdemeanor, …or when the conspiracy was defined by statute as a felony, … merger did not obtain. As these common-law procedural niceties disappeared, the merger concept lost significance, and today it has been abandoned. …
Petitioner does not draw on this archaic law of merger. He argues that Congress by combining the conspiracy and the substantive offense in one provision, §1951, manifested an intent not to punish commission of two offenses cumulatively. Unlike the merger doctrine, petitioner’s position does not question that the Government could charge a conspiracy even when the substantive crime that was its object had been completed. His concern is with the punitive consequences of the choice thus open to the Government; it can indict for both or either offense, but, petitioner contends, it can punish only for one.
The present Hobbs Act had as its antecedent the Anti-Racketeering Act of 1934. In view of this Court’s restrictive decision in United States v. Local 807, 315 U.S. 521 (1942), Congress, under the leadership of Representative Hobbs, sought to stiffen the 1934 legislation. After several unsuccessful attempts over a period of four years, a bill was passed in 1946 which deleted any reference to wages paid by an employer to an employee, on which the decision in Local 807 had relied. The 1934 Act was further invigorated by increasing the maximum penalty from ten to twenty years.
Petitioner relies on numerous statements by members of Congress concerning the severity of the twenty-year penalty to illustrate that cumulative sentences were not contemplated. But the legislative history sheds no light whatever on whether the Congressmen were discussing the question of potential sentences under the whole bill or merely defending the maximum punishment under its specific sections. All the legislative talk only reiterates what the statute itself says - that the maximum penalty is twenty years.
The distinctiveness between a substantive offense and a conspiracy to commit is a postulate of our law. “It has been long and consistently recognized by the Court that the commission of the substantive offense and a conspiracy to commit it are separate and distinct offenses.” … Over the years, this distinction has been applied in various situations. For example, in Clune v. United States, 159 U.S. 590, the Court upheld a two-year sentence for conspiracy over the objection that the crime which was the object of the unlawful agreement could only be punished by a $100 fine. The same result was reached when, as in the present case, both offenses were described within the same statute. In Carter v. McClaughry, 183 U.S. 365, cumulative sentences for conspiracy to defraud and fraud were upheld. “Cumulative sentences,” the Court pronounced, “are not cumulative punishments, and a single sentence for several offences, in excess of that prescribed for one offence, may be authorized by statute.” …
This settled principle derives from the reason of things in dealing with socially reprehensible conduct: collective criminal agreement - partnership in crime - presents a greater potential threat to the public than individual delicts. Concerted action both increases the likelihood that the criminal object will be successfully attained and decreases the probability that the individuals involved will depart from their path of criminality. Group association for criminal purposes often, if not normally, makes possible the attainment of ends more complex than those which one criminal could accomplish. Nor is the danger of a conspiratorial group limited to the particular end toward which it has embarked. Combination in crime makes more likely the commission of crimes unrelated to the original purpose for which the group was formed. In sum, the danger which a conspiracy generates is not confined to the substantive offense which is the immediate aim of the enterprise.
These considerations are the presuppositions of the separately defined crimes in §1951. The punitive consequences that presumably flow from them must be placed in such context. Congress is, after all, not a body of laymen unfamiliar with the commonplaces of our law. This legislation was the formulation of the two Judiciary Committees, all of whom are lawyers, and the Congress is predominately a lawyers’ body. We attribute “to Congress a tacit purpose - in the absence of any inconsistent expression - to maintain a long-established distinction between offenses essentially different; a distinction whose practical importance in the criminal law is not easily overestimated.” …
These considerations are reinforced by a prior interpretation of the Sherman Act whose minor penalties influenced the enactment of the 1934 anti-racketeering legislation. In American Tobacco Co. v. United States, 328 U.S. 781, individual and corporate defendants were convicted, inter alia, of conspiracy to monopolize and monopolization….. They were sentenced to a fine of $5,000, the maximum statutory penalty, on each of the counts. We affirmed these convictions on the basis of our past decisions in this field of law. … To dislodge such conventional consequences in the outlawing of two disparate offenses, conspiracy and substantive conduct, and effectuate a reversal of the settled interpretation we pronounced in American Tobacco would require specific language to the contrary. …
Petitioner argues that some of the other provisions of §1951 seem to overlap and would not justify cumulative punishment for separate crimes. From this he deduces a congressional intent that the statute allows punishment for only one crime no matter how many separately outlawed offenses have been committed. These contentions raise problems of statutory interpretation not now here. That some of the substantive sections may be repetitive as being variants in phrasing of the same delict, or that petitioner could not be cumulatively punished for both an attempt to extort and a completed act of extortion, has no relevance to the legal consequences of two incontestably distinctive offenses, conspiracy and the completed crime that is its object. In the American Tobacco litigation it was decided that the attempt to monopolize, described in §2 of the Sherman Act, merged with the completed monopolization, but this result did not qualify the holding that cumulative sentences for the conspiracy and the substantive crime, also contained within §2, were demanded by the governing precepts of our law.
Petitioner invokes “the rule of lenity” for decision in this case. But that “rule,” as is true of any guide to statutory construction, only serves as an aid for resolving an ambiguity; it is not to be used to beget one. “To rest upon a formula is a slumber that, prolonged, means death.” … The rule comes into operation at the end of the process of construing what Congress has expressed, not at the beginning as an overriding consideration of being lenient to wrongdoers. That is not the function of the judiciary. In United States v. Universal C. I. T. Credit Corp., 344 U.S. 218; Bell v. United States, supra, and Ladner v. United States, 358 U.S. 169, the applicable statutory provisions were found to be unclear as to the appropriate unit of prosecution; accordingly, the rule of lenity was utilized … to resolve the ambiguity. In Prince v. United States, 352 U.S. 322, and Heflin v. United States, 358 U.S. 415, the Court had to meet the problem whether various subsidiary provisions of the Federal Bank Robbery Act, 18 U.S.C. §2113, which punished entering with intent to commit robbery and possessing stolen property, merged when applied to a defendant who was also being prosecuted for the robbery itself. Again the rule of lenity served to resolve the doubt with which Congress faced the Court.
Here we have no such dubieties within the statute itself. Unlike all of these cases, the problem before us does not involve the appropriate unit of prosecution - whether conduct constitutes one or several violations of a single statutory provision - nor is it an open question whether conspiracy and its substantive aim merge into a single offense. This is an ordinary case of a defendant convicted of violating two separate provisions of a statute, whereby Congress defined two historically distinctive crimes composed of differing components. If petitioner had committed two separate acts of extortion, no one would question that the crimes could be punished by consecutive sentences; the result seems no less clear in the present case. It was therefore within the discretion of the trial judge to fix separate sentences, even though Congress has seen fit to authorize for each of these two offenses what may seem to some to be harsh punishment.