The report, released May 29 by the anti-graft group Mexicans Against Corruption and Impunity, found that unreported campaign financing may amount to as much as 15 times what is reported to election authorities.

According to the report, organized crime and corruption are major sources of illicit campaign financing in Mexico, as are private individuals seeking to curry favor with politicians.

The report found that past reforms designed to make Mexico’s electoral process more democratic and eliminate electoral fraud have “failed to prevent the penetration of illegal money” into campaigns. In addition, lax oversight and minimal fines for breaking the rules provide little incentive for politicians to ensure their campaign cash is clean.

In the last two decades, political parties have rarely been punished for violating campaign finance rules. And when they have been caught, the sanctions have been little more than slaps on the wrist, leading politicians to see them as simply part of the cost of running for office.

“The fines are like a toll that parties are willing to integrate into their cost and risk calculations in order to win elections,” the report’s authors write.

InSight Crime Analysis

The new report serves as a stark reminder of how crime groups and corrupt interests in Mexico and throughout the region pump money into political campaigns with the expectation of receiving protection or other favors from the state in return.

In one prominent case in Mexico, the former governor of Tamaulipas, Tomás Yarrington, has been accused of taking campaign money from the powerful Gulf Cartel and Zetas crime groups in exchange for essentially letting them take over the strategic border state.

In neighboring Guatemala, illicit campaign financing has been at the heart of various investigations into widespread corruption. Prosecutors say former President Otto Pérez Molina illegally took cash from donors during his 2011 run, paying them back with state contracts once he was elected. Current President Jimmy Morales has been accused of accepting some $500,000 from a drug trafficker during his 2015 presidential campaign.

Even as far away as Brazil, funding campaigns with dirty money was allegedly one of the main goals of the massive graft scheme that authorities there have been unraveling in recent years.

While illicit campaign financing remains a major problem, there is a growing recognition of the need to improve oversight and enforcement of laws governing political donations.

To address the issue, the report’s authors propose defining new criteria for campaign spending caps, creating new control mechanisms and increasing transparency, among other things.