Article I, Section 8, Clause 18:
[The Congress shall have Power . . . ] To make all Laws which shall be necessary and proper for carrying into Execution the foregoing Powers, and all other Powers vested by this Constitution in the Government of the United States, or in any Department or Officer thereof.
Building on the foundation established by McCulloch, modern Necessary and Proper Clause doctrine holds that the Clause permits any federal legislation that is convenient
or useful
to the exercise of federal power—that is, any means that is rationally related to the implementation of a constitutionally enumerated power.
1 The significance of this broad understanding of McCulloch on the powers of the federal government is difficult to overstate.2 Much federal law rests on the foundation established by McCulloch, and practically every power of the federal government has been expanded in some degree by the Necessary and Proper Clause.3 Under the authority granted it by the Clause, Congress has adopted measures required to comply with treaty obligations,4 organized the federal judicial system,5 regulated intrastate matters that substantially affect interstate commerce,6 seized property pursuant to its taxing powers,7 and exercised the power of eminent domain to acquire private property for public use.8
Perhaps most notably, nearly all federal criminal law that applies outside of federal enclaves9 relies on the Necessary and Proper Clause.10 The Constitution expressly empowers Congress to punish only four crimes: counterfeiting, piracies, offenses against the law of nations, and treason.11 The remainder of the federal criminal code—prohibitions on, for example, tax evasion, racketeering, mail fraud, and drug possession12 —rests on a determination that criminalization is necessary to effectuate congressional power to regulate interstate commerce, collect taxes, establish post offices, spend for the general welfare, or some other enumerated federal power.13 For example, as necessary and proper to Congress's authority under the Spending Clause, Congress may criminalize bribery of state and local officials receiving federal funds.14 Or, as necessary and proper to its power to regulate interstate commerce, Congress may prohibit intrastate cultivation and use of controlled substances such as illegal drugs.15
In United States v. Comstock, the Roberts Court addressed whether the Necessary and Proper Clause could support a federal law that provided for indefinite civil commitment of certain persons in federal custody who were shown to be sexually dangerous,
authorizing detention of such prisoners even after they had served their sentences.16 The difficulty with the law, as a matter of congressional power, was that sexual dangerousness was defined broadly, without an explicit tie to any enumerated federal power,17 such as an impact on commerce. Moreover, the Court's 2000 decision in United States v. Morrison foreclosed the argument that Congress could regulate general sexual violence pursuant to the Commerce Clause.18
The Court in Comstock upheld the civil commitment provision under the Necessary and Proper Clause. Writing for a five-Justice majority, Justice Breyer held that whatever enumerated power justified the prisoner's crime of conviction19 permitted Congress to provide appropriately for those imprisoned, and to maintain the security of those who are not imprisoned but who may be affected by the federal imprisonment of others,
including through post-sentence civil commitment.20 This conclusion was justified by five factors:
(1) the breadth of the Necessary and Proper Clause, (2) the long history of federal involvement in this arena, (3) the sound reasons for the statute's enactment in light of the Government's custodial interest in safeguarding the public from dangers posed by those in federal custody, (4) the statute's accommodation of state interests, and (5) the statute's narrow scope.21
In 2013, the Supreme Court reaffirmed Comstock's reasoning in United States v. Kebodeaux.22 Like Comstock, Kebodeaux concerned a federal regulation of sex offenders: the registration requirements of the 2006 Sex Offender Registration and Notification Act (SORNA).23 Anthony Kebodeaux, a member of the U.S. Air Force, was convicted by a court martial of a sex crime in 1999; he served a three-month sentence and received a bad conduct discharge.24 In 2007, Kebodeaux was convicted of violating SORNA when he moved from El Paso to San Antonio but failed to update his registration.25
Although Congress did not enact SONRA until after Kebodeaux's court martial and discharge, the Supreme Court upheld its application to Kebodeaux as necessary and proper to Congress's power to make Rules for the . . . Regulation of the land and naval Forces.
26 Key to that conclusion was the Court's finding that Kebodeaux's release from federal custody was not unconditional
because, as part of his original punishment by the court martial he was subject to an earlier federal statute, the Wetterling Act, which imposed very similar
registration requirements to those of SORNA.27 The Court thus framed the case as presenting a narrow question of whether Congress could later modify
the Wetterling Act's registration requirements through SORNA.28 Applying the five Comstock factors, the Court concluded that the breadth of the Necessary and Proper Clause and the reasonableness of Congress's registration requirements justified SORNA's application to Kebodeaux.29
Although Comstock and Kebodeaux embrace a broad, relatively deferential understanding of the Necessary and Proper Clause, the Supreme Court has at times taken a narrower view, especially in cases involving independent federalism concerns.30 In the Commerce Clause context, for example, the Rehnquist Court found the Necessary and Proper Clause insufficient to support laws prohibiting possession of guns near schools31 and prohibiting gender-motivated violence,32 despite arguments that these activities have an aggregate impact on interstate commerce. These cases are discussed in greater detail elsewhere in the Constitution Annotated.
Similarly, just two years after Comstock, five Justices separately concluded that the individual mandate
provision of the Affordable Care Act (ACA), which required individuals to purchase insurance or pay a tax penalty, exceeded Congress's power under the Commerce and Necessary and Proper Clauses.33 In National Federation of Independent Business v. Sebelius (NFIB), Chief Justice Roberts's opinion reasoned that the individual mandate was not an essential component
of the ACA's health insurance reforms because it operated to vest[] Congress with the extraordinary ability to create the necessary predicate to the exercise of an enumerated power
by compelling individuals to engage in commerce.34 Therefore, unlike the law in Comstock, the authority Congress attempted to exercise in NFIB was neither narrow in scope
nor incidental
to the exercise of Commerce Clause power.35 However, a majority of the Court ultimately held that the individual mandate was authorized under Congress's power to lay and collect taxes.36