Legislative Branch in Mexico

Introduction

The Legislative Power is vested in the Congress of the Union (Congreso de la Unión), a bicameral body composed of the Chamber of Deputies and the Senate of the Republic. Articles 50 through 79 of the Constitution establish the structure, composition, powers, and procedures of the federal legislature. Congress exercises legislative, budgetary, oversight, and appointment powers.

Chamber of Deputies

The Chamber of Deputies (Cámara de Diputados) comprises 500 members elected every three years: 300 elected by plurality in single-member districts (distritos uninominales) and 200 elected through proportional representation (representación proporcional) from multi-member regions. The proportional representation system ensures minority party representation. The Chamber has exclusive powers over the federal budget, revenue laws, and the review of public accounts.

Senate of the Republic

The Senate (Cámara de Senadores) comprises 128 members elected every six years: 96 elected by plurality (three per state and Mexico City) and 32 elected through proportional representation. The Senate has exclusive powers over foreign policy (treaty ratification, diplomatic appointments), the appointment of certain officials (including the Attorney General and SCJN ministers), and the approval of military commitments.

Legislative Process

The legislative process (Articles 71 and 72) begins with a bill (iniciativa) introduced by the President, members of Congress, state legislatures, or citizens (through popular initiative). The bill is considered in committee, debated on the floor of each chamber, and must be approved by both chambers and signed by the President. The President may veto legislation, subject to a two-thirds override by Congress.

Congressional Standing Committees

Congress operates through standing committees (comisiones ordinarias) that review legislation and conduct oversight. Key committees include Finance, Constitutional Affairs, Justice, Human Rights, and National Defense. Committees may summon secretaries of state and other officials to testify. The permanent committee (Comisión Permanente) functions during congressional recesses.

Oversight Powers

Congress exercises oversight through: the review of the federal budget and public accounts; the power to summon officials to testify; audit powers exercised through the Superior Audit Office of the Federation (ASF); and the power to approve or reject presidential appointments. The Chamber of Deputies has the power to impeach senior officials, and the Senate conducts the trial.

Conclusion

The Mexican Congress is a bicameral legislature with broad legislative, budgetary, and oversight powers. The mixed electoral system ensures both territorial representation and proportional minority representation. The legislative process balances congressional authority with presidential initiative through veto and override mechanisms.