Mexico took a giant step toward ending marijuana prohibition Wednesday night as the Chamber of Deputies approved a legalization bill on a vote of 316-129. The Senate approved the bill late last year, and President Andres Manuel Lopez Obrador has signaled he will sign it into law.

But it's not quite a done deal yet. Because the bill was amended in the Chamber of Deputies -- and lawmakers were still debating possible amendments late Wednesday night -- it must now go back to the Senate for approval of the changes.

Still, Mexico, a country legendary for marijuana production since the days of the hippies, is now on the verge of becoming the world's largest legal marijuana market. In the United States, federal marijuana prohibition still obtains despite state-level legalization in an ever-increasing number of states, potentially (and ironically) leaving the US as the odd man out in North America, sandwiched between legal pot pioneers Canada and Mexico.

The legislative move to legalize marijuana is the outgrowth of a Mexican Supreme Court decision three years ago that held marijuana prohibition unconstitutional and gave the congress a limited amount of time to bring the law into compliance with the constitution. Deadlines were repeatedly bumped back, though, especially as the coronavirus took hold, but now the congress was up against another deadline next month. And this time, it beat it.

Under the bill, people 18 and up will be able to possess up to an ounce of marijuana and grow up to six plants (although one controversial change in the Chamber of Deputies would require home growers to register with the state). The bill also creates a system of taxed and regulated legal marijuana commerce. In another change from the Senate bill, this bill would give regulatory control over the new legal industry to the National Commission Against Addictions instead of the independent regulatory body envisioned by the upper house.

Activists bemoaned aspects of the bill, with Mexico Unido Contra la Delinquencia (MUCD) complaining that it represented a "lost opportunity to end the criminalization of users" because it maintains penalties for possession of larger amounts and that it "did not eliminate the crime of cultivation for persons of scarce resources and extreme economic necessity who have dedicated themselves to this as a primordial activity." This would "perpetuate the marginalization and criminal punishment of our peasants, the people most affected by prohibition, who we want to integrate into the market, not maintain in illegality."

MUCD is calling on the Senate to rectify the bill to address such issues. "Above all, we must not create a legal market that only prioritizes the economic benefit of those who participate in sales while we exclude other, less advantaged actors," the group said. "For this, we call on the Senate of the Republic to correct the bill to comply with the mandate of the Supreme Court to eliminate the absolute prohibition of the consumption of cannabis."

Still, despite the objections raised by MUCD and others, Mexico is on the verge of shifting from a prohibition regime to legal marijuana regime, and that is a big deal, and a recognition that the country has bigger problems to deal with.

"The damage caused by the prohibition and the war on drugs in Mexico has caused more harm than the health conditions attributed to drug consumption," said Dep. Rubén Cayetano García. "Cannabis is not considered one of the serious public health problems in Mexico."

"For Mexico, given its size and its worldwide reputation for being damaged by the drug war, to take this step is enormously significant," said John Walsh, director of drug policy for the Washington Office on Latin America. "North America is heading toward legalization."