A number of amendments to the United States Constitution include a Congressional power of enforcement. The language "The Congress shall have power to enforce this article by appropriate legislation" is used, with slight variations, in Amendments 13, 14, 15, 18, 19, 23, 24, and 26. The variations in the pertinent language are as follows: the Thirteenth Amendment leaves out the "the", the Fifteenth Amendment states "The Congress shall have the power to enforce, by appropriate legislation, the provisions of this article." and the Eighteenth Amendment states "The Congress and the several States shall have concurrent power to enforce this article by appropriate legislation."

These provisions made their first appearance in the Thirteenth, Fourteenth and Fifteenth Amendments, which were adopted during the Reconstruction period primarily to abolish slavery and protect the rights of the newly emancipated African-Americans. The enforcement provisions contained in these amendments extend the powers of Congress originally enumerated in Article One, Section 8 of the Constitution, and have the effect of increasing the power of Congress and diminishing that of the individual states.

The Supreme Court of the United States has held that the Congressional power to enforce the Fourteenth Amendment creates an exception to the doctrine of state sovereign immunity that the Court has developed under the Eleventh Amendment. Thus, a law properly enacted under the enforcement provision in Section 5 of the Fourteenth Amendment can authorize private individuals to sue a U.S. state in federal court. Under the Court's current view, the same is not true of a law enacted under Congress's Article One powers.

Interpretation of the Fourteenth Amendment's enforcement provision has been the subject of several important Supreme Court cases, which reflect the tension between the Courts' role of interpreting the Constitution and Congress's power of adopting legislation to enforce specific Constitutional amendments.

Early on, in the so-called Civil Rights Cases decided in 1883, the Supreme Court took a narrow view of Congress's enforcement power. In that case, the Court concluded that the Congressional enforcement power in Section 5 of the Fourteenth Amendment did not authorize Congress to ban racial discrimination in public accommodations operated by private persons, such as inns and theaters. The Court stated that since the Fourteenth Amendment only restricted state action, Congress lacked power to forbid discrimination that was not sponsored by the state. In modern times, similar civil rights legislation has been upheld under Congress's power to regulate interstate commerce under Article One, Section 8 of the Constitution. See Civil Rights Act of 1964.

In the Katzenbach v. Morgan case, decided in 1966, the Supreme Court appeared to take a broader view of the Congressional power of enforcement. In that case, the Court concluded that Congress can forbid practices that are not themselves unconstitutional, if the law is aimed at preventing or remedying constitutional violations. On that basis, the Court upheld a provision of the Voting Rights Act that prevented states form using English language literacy tests as qualifications for voting. The Court decided that the law was a valid exercise of Congress's enforcement power under the Fourteenth Amendment, because it was aimed at remedying state-sponsored discrimination.

In 1970, however, in Oregon v. Mitchell, the Court held that Congress had exceeded its power by attempting to require the states to reduce the voting age to 18. This led to adoption of the Twenty-Sixth Amendment to the Constitution in 1972, which provided that the states could not set a minimum voting age higher than 18.

In the 1997 case of City of Boerne v. Flores, the Court again took a narrow view of the Congressional power of enforcement, striking down a provision of the Religious Freedom Restoration Act (RFRA) that sought to forbid the states from placing burdens on religious practice in the absence of a compelling state interest in doing so. In enacting RFRA, Congress had sought to overturn the 1988 Supreme Court decision in Employment Division v. Smith, which had held that the Constitution does not require states to recognize religious exemptions to laws of general applicability. In the Boerne case, the Supreme Court decided that RFRA overstepped Congress's authority, because the statute was not sufficiently connected to the goal of remedying a constitutional violation, but instead created new rights that are not guaranteed by the Constitution. Some observers have suggested that the Supreme Court saw RFRA as a threat to the Court's institutional power and an incursion on its role as final arbiter of the meaning of the Constitution, because that statute was aimed specifically at overturning the Employment Division v. Smith decision.

The Supreme Court also read Congress's enforcement powers narrowly in United States v. Morrison, decided in 2000. In Morrison, the Court overturned provisions of the Violence Against Women Act (VAWA), that criminalized gender-based violence. Relying on The Civil Rights Cases, Boerne and other precedents, the Court held that Congress did not have power to forbid discrimination against women in the absence of a connection to state action or interstate commerce.