Inside the risky U.S. probe of allegations that drug mafias financed Obrador campaign

In the summer of 2010, as U.S. agents dug into allegations that a powerful drug mafia had poured money into Mexican politics, the investigators took direct aim at the man who is now the country’s president, Andrés Manuel López Obrador.

According to confidential government documents obtained by ProPublica, the Drug Enforcement Administration knowingly risked a political furor to try to penetrate López Obrador’s campaign organization before Mexicans could elect a government that might be beholden to the traffickers.