The Mexican Senate Tuesday approved a bill that would decriminalize the possession of small amounts of drugs in a bid to undercut Mexican drug trafficking organizations and free police to go after them instead of drug users. The bill was backed by the conservative government of President Felipe Calderón.

[inline:mexicomap.jpg align=right caption="map of Mexico (from state.gov)"]Under the bill, personal use quantities of drugs could be possessed without criminal liability. The quantities include up to five grams of marijuana, a half gram of cocaine, and smaller quantities of drugs such as heroin and methamphetamine.

The bill would also shift the prosecution of low-level drug dealers to the states by making it no longer a federal crime to sell drugs. The federal government currently prosecutes all drug trafficking offenses, but because federal courts are busy trying higher-level drug traffickers, the cases of lower-level offenders rarely get tried.

The Mexican Congress passed a similar measure in 2006 under President Vicente Fox, but Fox vetoed that bill under pressure from the US. Now, after 10,000 deaths in 2 1/2 years of Calderón's drug war, Mexico appears less inclined to heed US demands to not decriminalize -- and given the change of administration in Washington, the US seems less likely to demand Mexico remain a drug war hardliner when it comes to small-time possession cases.

The measure must still pass the Chamber of Deputies. The congressional session was supposed to end Thursday, but there is some chance it will be extended because of the flu emergency in the capital.

"We celebrate that the legislators have agreed with the proposals of the Social Democratic Party," Mexico City PSD leader Razú Aznar told the official news agency Notimex after the vote. "Our platform proposes that we take legislative measures to eliminate criminal charges against addicts and help them into therapy in a voluntary manner and that they be treated by specialists," he said.

But decriminalization is only a first step, said Razú Aznar. "It is clear for the PSD that the regularization of drugs is at this time one of the best alternatives to reduce the profits of organized crime and eradicate the practice of violence."

Decriminalization may only be a first step, but as of this writing, the Mexican Congress has only completed half of that first step.