COOK, J., delivered the opinion of the court, in which BEER, D.J., joined. BOGGS, C.J., (pp. 350-353), delivered a separate opinion concurring in part and dissenting in part.
OPINION
COOK, Circuit Judge.Patrick Wayne Madden appeals his conviction and sentence for violating the federal vote-buying statute, 42 U.S.C. § 1973i(c). Because Madden’s plea agreement waived his right to challenge his conviction, we dismiss that aspect of his appeal. As regards his sentence, we conclude that the district court erred by applying the vulnerable-victim enhancement. We therefore remand for resentencing.
I
Madden paid three people to vote for a candidate for local office in a primary election. Because the ballot included candidates for United States Senate — though Madden did not offer anyone money to vote for a Senate candidate — the government charged Madden with violating the federal vote-buying statute.
Madden pleaded guilty to one count of vote-buying pursuant to a written plea agreement. Part of the agreement provided: “The Defendant waives the statutory right to appeal the guilty plea and conviction.” Despite waiving this right, Madden now challenges his conviction, arguing that the statute does not prohibit buying votes for non-federal candidates, or, if it does, the statute is unconstitutional.
Madden’s plea allows an appeal of his sentence, and, in that regard, Madden targets enhancements and a Booker Sixth Amendment violation as sentencing errors by the district court.
II
A. Madden Waived His Right to Appeal His Conviction
Madden’s plea agreement foreclosed appeal of his conviction, and this court enforces such waivers. United States v. Bazzi, 94 F.3d 1025, 1028 (6th Cir.1996). Madden nevertheless seeks to avoid the consequences of his plea by styling his conviction challenge as jurisdictional, advancing both a statutory and a constitutional argument. He first posits that § 1973i(c) prohibits only buying votes for federal candidates — a prohibition not violated by his conduct. In the alternative, Madden says that if § 1973i(c) does criminalize buying votes for state or local candidates, then the statute is unconstitutional. According to Madden’s theory, federalism principles deprive Congress of the power to criminalize buying votes for candidates in state or local elections because the mere presence of a federal candidate on the same ballot is an insufficient federal interest to give Congress regulatory power. Madden thus reasons that the district court lacked jurisdiction to convict him for vote buying- — where he bought votes only *349for local candidates — either because Congress did not intend to prohibit such vote buying or because Congress lacks the power to prohibit such vote buying.
Madden confuses congressional power to criminalize conduct with federal subject-matter jurisdiction. Even if the vote-buying statute fails the sufficient-federal-interest test, such a non-jurisdictional challenge is waived by Madden’s plea agreement. The district court’s power to convict Madden comes from its jurisdiction “of all offenses against the laws of the United States.” 18 U.S.C. § 3231. Madden pleaded guilty to violating § 1973i(c) — an offense against the United States.
In United States v. Rayborn this court considered a similar subject-matter jurisdiction argument, and reversed a district court’s dismissal of an arson prosecution. 312 F.3d 229, 231 (6th Cir.2002). The district court decided it lacked subject-matter jurisdiction to hear the case because the building burned by the defendant was not “used in interstate or foreign commerce or in any activity affecting interstate or foreign commerce,” as required by 18 U.S.C. § 844(i). But this court held that § 844(i)’s interstate-commerce requirement, while an element of the crime, was not a prerequisite for the district court’s subject-matter jurisdiction. Id. (“Although the interstate commerce requirement is frequently called the ‘jurisdictional element,’ it is simply one of the essential elements of § 844(i). It is not jurisdictional in the sense that it affects a court’s subject matter jurisdiction, ie., a court’s constitutional or statutory power to adjudicate a case.”); see also Hugi v. United States, 164 F.3d 378, 380-81 (7th Cir.1999) (“A link to interstate commerce may be essential to Congress’s substantive authority ... but the existence of regulatory power differs from the subject-matter jurisdiction of the courts.”). Thus, even if we assume that Congress lacks the power to punish non-federal candidate vote buying, such a constitutional infirmity in § 1973i(c) would not deprive the district-court of subject-matter jurisdiction to accept Defendant’s guilty plea.
B. Sentencing Issues
1. Supervisory-Role Enhancement
The district court applied the U.S.S.G. § 3Bl.l(e) supervisory-role enhancement and increased Madden’s base offense level by two levels. Madden argues that applying the supervisory-role enhancement constitutes impermissible double counting because the supervision he exercised was nó more than necessary to establish a vote-buying offense. Madden’s argument fails, however, because the mere act of paying for a vote violates § 1973i(c) regardless of the degree of supervision the vote buyer provides. Here, Madden did more than merely pay for votes; he also transported voters to the polls and, in the case of one vote seller, voted that person’s ballot. Hence, the district court properly applied the supervisory-role enhancement.
2. Vulnerable-Victim Enhancement
Madden next argues .that the district court erred by applying the vulnerable-victim ■ enhancement under U.S.S.G. § 3A1.1(b)(1), which provides a two-level enhancement if “the defendant knew or should have known that a victim of the' offense was a vulnerable victim.” Madden acknowledges that he knew the mentally ill people who sold their votes were vulnerable, but maintains- they were not victims because they received fifty dollars for their votes.
Although we have found no precedent directly on point, we agree that the vote sellers here were not “victims” for Guidelines purposes. The Guidelines elsewhere acknowledge that for some crimes, includ*350ing drug offenses, the victim is “society at large,” rather than any individual. U.S. Sentencing Guidelines Manual § 3D1.2, cmt. n. 2 (2004). If a drug buyer — who chooses to harm himself through drug consumption — is not a “victim,” then neither is someone who accepts payment for his vote. The vote-buying statute protects “society at large” from corruption of the electoral process; it does not protect, but rather restrains, individuals who value money more highly than their right to vote in a given election. Therefore, the vulnerable-victim enhancement was inappropriate here, because the alleged victims were not victims at all.
The cases Chief Judge Boggs cites in his partial dissent to support his contrary view are distinguishable from this case. United States v. Mautner is, of course, unpublished and non-binding, and involved mail fraud, a crime that always involves at least one victim. No. 97-3596, 1999 WL 55273 (6th Cir. Jan. 13, 1999). Mautner simply affirmed the district court’s factual finding that particular individuals were victims — it did not address, as we do, the purely legal question of whether a particular crime can have victims at all.
In United States v. Gawthrop, the district court concluded that a vulnerable-victim enhancement was appropriate not for the offense of conviction, but for other “relevant conduct,” including sexual abuse. 310 F.3d 405, 410-11 (6th Cir.2002). Here, in contrast, the district court proceeded as though the “victims” were victims of the offense of conviction itself. And we conclude as a legal matter that Madden’s crime of vote-buying can have no victim other than society at large.
In United States v. Amedeo, the defendant violated 21 U.S.C. § 859(a), which punishes drug sales to individuals under age twenty-one more severely than federal law punishes ordinary drug sales. 370 F.3d 1305, 1309 (11th Cir.2004). Thus, the defendant was convicted under a statute that contemplated a victim — the minor drug buyer (as “minor” was defined at the time of the law’s 1970 enactment). The Mann Act similarly exists to protect a particular class of people: women supposedly forced into prostitution. See Wyatt v. United States, 362 U.S. 525, 530, 80 S.Ct. 901, 4 L.Ed.2d 931 (1960) (“As the legislative history discloses, the [Mann] Act reflects the supposition that the women with whom it sought to deal often had no independent will of their own, and embodies, in effect, the view that they must be protected against themselves.”).
As for the argument that this case resembles one of “voter intimidation and coercion,” Madden was not convicted of that crime — he was convicted only of buying votes. And the fact that he paid his “victims” fifty dollars each suggests, if anything, a lack of intimidation or coercion.
Because the district court erred by applying the vulnerable-victim enhancement, we remand for resentencing. This remand makes it unnecessary for us to address Madden’s Booker arguments because, on remand, the district court must apply the Guidelines in light of Booker.
Ill
We dismiss Madden’s appeal of his conviction, and we vacate Madden’s sentence and remand for resentencing.