Constitutional Amendment Process in Mexico

Introduction

The constitutional amendment process in Mexico is governed by Article 135 of the Constitution, which establishes the procedure for reforming the supreme law. Unlike rigid constitutions with extraordinary amendment requirements, Mexico’s amendment process is relatively flexible, having been used over 700 times since 1917. The process requires approval by Congress and ratification by state legislatures.

The Amendment Procedure

Article 135 provides that Congress, by a vote of two-thirds of the members present in each chamber, may approve constitutional amendments. The approved amendment is then submitted to state legislatures, and ratification requires approval by a majority of state congresses (17 of 32). Once ratified, the amendment is promulgated and published. Congress determines the amendment’s effective date.

Limitations on Amendment

The Constitution does not contain explicit “eternity clauses” limiting the scope of amendments. However, the SCJN has recognized implicit limitations derived from the Constitution’s fundamental principles and structure. The Court in Controversia Constitucional 82/2005 held that amendments cannot destroy the essential elements of the constitutional order, including the republican form of government, the separation of powers, and fundamental rights.

Major Reforms

Significant constitutional reforms include: 1992 (constitutional recognition of churches and religious liberties), 2011 (human rights reform, Articles 1 and 103), 2013–2014 (energy reform, Articles 25, 27, and 28), 2014 (electoral reform), 2019 (gender parity), and 2024 (judicial reform, popular election of judges). The 2011 human rights reform is widely regarded as the most significant single amendment.

Judicial Review of Amendments

The SCJN has asserted jurisdiction to review constitutional amendments through actions of unconstitutionality and constitutional controversies. While the Court generally shows deference to the constituent power, it has reviewed whether amendments followed proper procedure and whether they violate implicit constitutional limits. This power of judicial review over amendments reflects the Court’s role as guardian of the Constitution.

Conclusion

The constitutional amendment process under Article 135 balances flexibility with federalism, requiring both supermajority congressional approval and state ratification. The frequent use of the amendment power has allowed the Constitution to adapt to changing circumstances while maintaining its essential character.