The constitutional reform is controversial because it would completely remake Mexico's judiciary. One side says it would end corruption, the other that it would end judicial independence.
In Mexico, a group of masked people in the state of Chiapas stopped presidential candidate Claudia Sheinbaum at a checkpoint. The incident comes amid a spate of political assassinations.
Mexicans will vote this Sunday in the largest elections the country has ever had. The midterm vote is also becoming one of the most violent, with 35 candidates killed so far.
