Early last year, when the death toll from Mexican President Felipe Calderon's crackdown on the cartels stood at 35,000 or so, Michele Leonhart, head of the U.S. Drug Enforcement Administration, told reporters in Cancun "the unfortunate level of violence is a sign of success in the fight against drugs." The results of last week's presidential election, in which the candidate of Calderon's National Action Party (PAN) finished a distant third, suggest Mexican voters are no longer buying that counterintuitive argument, if they ever did.

Even if "the fight against drugs" were winnable, it would be an outrageous imposition. Why should Mexicans tolerate murder and mayhem on an appalling scale (more than 50,000 deaths since Calderon launched his assault in December 2006), not to mention the rampant corruption associated with prohibition, all in the name of stopping Americans from obtaining psychoactive substances that their government has arbitrarily decreed they should not consume? That sort of arrogant expectation is becoming increasingly untenable.

Mexico's incoming president, Enrique Pena Nieto of the Institutional Revolutionary Party (PRI), has promised continued cooperation with U.S. drug warriors. But during the campaign, he and the other two leading candidates all said controlling violence, as opposed to seizing drugs or arresting traffickers, would be their top law enforcement priority. Pena Nieto has reiterated that commitment since the election, saying his success should be measured by the homicide rate.

At the same time, Pena Nieto has declared the current approach to drugs a failure and called for a "broad debate," including the possibility of legalization, while emphasizing that he personally opposes that option. The president-elect's mixed signals of continuity and change were reflected in a whipsawing Bloomberg headline: "Pena Nieto to Expand Drug War, Debate Drug Legalization."

Pena Nieto's lip service to reform might not amount to much on its own, but it takes on added significance in the context of recent rumblings from other politicians. Calderon's predecessor, Vicente Fox, who as president supported decriminalizing simple possession of drugs (a policy approved under Calderon), three years ago declared that "it's time to open the debate over legalizing drugs," adding that "it can't be that the only way is for the state to use force."

Last year Calderon himself expressed a similar frustration. "If [the Americans] are determined and resigned to consume drugs," he said in an eyebrow-raising speech, "then they should seek market alternatives in order to cancel the criminals' stratospheric profits, or establish clear points of access [to drugs]. But this situation can't go on."

In recent years that sentiment has been expressed by a growing number of Latin American leaders, beginning with Honduran President Manuel Zelaya in 2008. The following year, a commission convened by three former Latin American presidents—Fernando Henrique Cardoso of Brazil, César Gaviria of Colombia, and Ernesto Zedillo of Mexico—concluded that "prohibitionist policies based on the eradication of production and on the disruption of drug flows as well as on the criminalization of consumption have not yielded the expected results."

Furthermore, Cardoso et al. observed, the war on drugs has been accompanied by "a rise in organized crime," "a growth in unacceptable levels of drug-related violence," "the criminalization of politics and the politicization of crime," and "the corruption of public servants." They called for a "paradigm shift," including marijuana decriminalization. Since then we have heard similar talk from Colombian President Juan Manuel Santos, Guatemalan President Otto Perez Molina, Costa Rican President Laura Chinchilla, and Uruguayan President José Mujica.

Is America listening? At last April's Summit of the Americas in Cartagena, President Barack Obama, who as a U.S. Senate candidate in 2004 called the war on drugs "an utter failure," said "it is entirely legitimate to have a conversation" about whether the drug laws "are doing more harm than good in certain places." But he immediately added that "legalization is not the answer." In other words, even if prohibition does more harm than good, Obama is determined to stick with it.

Jacob Sullum is a senior editor at Reason and a nationally syndicated columnist. Follow him on Twitter.