Thousands of striking judges and court workers. A diplomatic spat with the United States. An exceptionally powerful leader vowing to defy his critics.

President Andrés Manuel López Obrador of Mexico is seeking to push a huge reorganization of his country’s judicial system through Congress. He wants nearly all of Mexico’s more than 7,000 judges to be elected instead of appointed, saying the changes are needed to instill trust in a judiciary viewed by many Mexicans as a bastion of corruption, influence-peddling and nepotism.

The proposed measures could produce one of the most far-reaching judicial overhauls of any major democracy. Relatively few countries allow judges to be elected on a significant scale — examples include the United States, Switzerland and Bolivia — but none to the degree that Mr. López Obrador is proposing, according to legal scholars.

“I feel 100 percent confident that this is anomalous on the international scale, no matter how you swing it,” said Mitchel Lasser, a law professor at Cornell Law School who has written about the different ways of selecting judges around the world.

Critics of the proposal contend the plan would do little to fix problems like graft and impunity. Instead, they argue, the overhaul is designed to enhance the power of Mr. López Obrador’s nationalistic political movement.

Tensions around the proposals are spilling into the streets of the world’s largest Spanish-speaking country as protesters try to stymie the plan.