Mexico’s Contentious Judiciary Overhaul Becomes Law

Mexico passed into law on Sunday a constitutional amendment remaking its entire judiciary, marking the most far-reaching overhaul of a country’s court system ever carried out by a major democracy.

The results demonstrate the exceptional influence of President Andrés Manuel López Obrador of Mexico, who championed the legislation. The victory of his allies in June elections afforded them substantial legislative majorities to advance the contentious proposal in the leader’s final weeks in office. On the eve of Mexico’s Independence Day, the measure was published in the government’s official gazette, making it law.

The law shifts the judiciary from an appointment-based system, largely grounded in training and qualifications, to one where voters elect judges and there are fewer requirements to run. That puts Mexico onto an untested course, the consequences of which are difficult to foresee.

“Now it’s different,” Mr. López Obrador said in a video posted on social media on Sunday night in which his successor, Claudia Sheinbaum, was seated next to him. “Now it’s the people who rule, the people who decide.”

Roughly 7,000 judges, from the chief justice of the Supreme Court down to those at local courts, will have to run for office under the new system. The changes will be put into effect gradually, with a large portion of the judiciary up for election in 2025 and the rest in 2027.

The government said the overhaul was needed to modernize the courts and to instill trust in a system plagued by graft, influence peddling and nepotism. Ms. Sheinbaum, takes office on Oct. 1 and has fully backed the plan.