In November 2015, the Mexican Supreme Court ruled that four individuals from the Mexican Society for Responsible and Tolerant Personal Use (SMART) would be permitted to grow and consume their own cannabis. The court ruled that prohibiting people from growing the drug for personal consumption, personal use and private consumption was unconstitutional as it violated the human right to the free development of one's personality. The case followed several years of patient work by México Unido Contra Delincuencia (MUCD), involving the development of individual cases which could test the legal status of prohibition (so-called ‘strategic litigation’).
After the 2015 ruling, more similar cases followed. On 31 October 2018, the Supreme Court ruled that the law prohibiting recreational use of cannabis in Mexico was unconstitutional for the fifth time. Under Mexican law this fifth ruling set a binding precedent across the country's court system — rather than only applying to the individual litigants. The effect of the ruling was that while the law prohibiting cannabis remained in place, it could no longer be meaningfully enforced, since anyone could cite the ruling and demand that their charges be thrown out. Crucially, the ruling also mandated that the government of Mexico move to formally legalise and regulate cannabis within the next 90 days.
The challenging and contentious process of devising a cannabis regulation Bill has led to the 90 day deadline being extended 3 times by the Court — with April 30th of 2021 now being the final deadline.