Mexico bans dual nationals — Mexican President Claudia Sheinbaum has enacted a constitutional reform that prohibits individuals holding dual nationality from seeking the country’s highest elected offices. The decree, signed on October 7, 2026, bans such candidates from running for president, state governor, or head of government of Mexico City.

The law requires candidates for these positions to formally renounce any other nationality before registering their candidacy. The provision was ratified by both houses of the federal congress and the required number of state legislatures.

Although effective immediately, the new rules will first apply to the 2028 electoral process. Sheinbaum and her legal counsel, Luisa María Alcalde, presented the measure as a safeguard to prevent foreign interference in Mexico’s political affairs.

The reform marks a significant shift in the criteria for political leadership, emphasizing exclusive national allegiance for those seeking to hold the nation’s highest offices.