Mexican National Guard troops massacred six migrants Tuesday in the southernmost state of Chiapas, only hours after the inauguration of the nominally “left” President Claudia Sheinbaum, who replaced her mentor Andrés Manuel López Obrador.

Soldiers rained down bullets on a pick-up truck carrying 33 migrants. The driver then lost control and the vehicle tipped over. Those who died had been shot in the head and the back, and 10 survivors were injured, several with critical wounds.

Three of the dead were from Egypt, and the others from Peru, Honduras and El Salvador. Among the survivors, there were migrants from Nepal, Cuba, India and Pakistan.

The Defense Ministry claims that three pick-up trucks dodged a checkpoint at high speed at 8:50 p.m., which led to a short pursuit. Soldiers then shot at a truck after reportedly hearing “two detonations.” The migrants were unarmed.

The statement says the trucks looked like those used by gangs, but they are precisely the types of trucks, which have closed livestock pens in the back, that are used to transport migrants as well as Mexican workers traveling to farms and other worksites.

The massacre took place along the Villa Comaltitlán-Huixtla highway commonly used by migrants as they leave the city of Tapachula that sits on the border with Guatemala.

In a press conference on Thursday, Sheinbaum said coldly: “First, this is a regrettable act and has to to be investigated and punished.” The two soldiers involved were placed in custody, she added.

The one point she stressed was that the Federal Prosecutor’s Office will investigate the case and not leave it in the hands of the military. A few hours later, however, the federal prosecutor issued its own statement backing the account of the military and adding that the soldiers were responding to a call about “armed people,” and that not only did the soldiers report hearing detonations, but “were attacked ... and because of this, repelled the attack, detaining a green pick-up truck while the other two vehicles fled.”

At no point has Sheinbaum questioned the use of soldiers trained to kill and with a long and prevalent record of extrajudicial executions, torture and other human rights abuses for “migrant contention” and “public security.”

So much for her campaign promises of a human-rights-based approach to migration, which has become the first casualty in terms of her credibility.

She has also defended López Obrador’s last major act in office: to use the super-majority won by his coalition in Congress to pass a constitutional reform that places the National Guard under the control of the military and the Ministry of Defense.

Since his administration created the National Guard in 2019, its main function has been to harass and detain migrants as an extension of the US Border Patrol, working alongside tens of thousands of troops from other branches of the military and migration officials.

In the first five months of 2024, the Mexican government detained 590,401 migrants and is expected to surpass the record 782,176 detentions registered in all of 2023.

The government maintains a sprawling system of 198 migration checkpoints, 54 permanent migrant detention camps and 348 “provisional” ones. While initially aimed against migrant workers, this represents the scaffolding for a police state regime aimed at repressing the coming mass struggles by Mexican workers.

A publication by Oxford University researcher Guadalupe Chavez reviews the migration policies under López Obrador and concludes that his administration “leveraged the northern border as a bargaining chip.” The result has been a record of “increased detentions, violence and migrant deaths.”

Chavez adds:

The INM [National Migration Institute] and the National Guard have been accused of raiding shelters and harassing migrants. In 2023, both parties raided Border Line Crisis Center, a shelter in Tijuana for women and children. In 2021, the National Guard killed a Cuban migrant after opening fire at a pick-up truck carrying migrants. That same year, a Guatemalan migrant was killed by Mexican soldiers at a migrant checkpoint. Migrants in transit face various forms of violence from the INM, the National Guard, and law enforcement agencies, forcing them to use dangerous routes controlled by criminal organisations.

One could add to this record the 2023 fire at a detention center in Ciudad Juarez where officials let 40 migrants burn alive, and the 2021 massacre in Camargo of 17 Guatemalan migrants and two Mexicans at the hands of the police.

The UN International Organization for Migration declared the US-Mexico border the deadliest in the world, having recorded over 2,980 deaths since 2014, undoubtedly a mere fraction of the real toll.

A massive escalation of the crackdown in Mexico was primarily responsible for cutting in half the number of US Border Patrol encounters with migrants at the southwest border after they reached a historic peak in December 2023. After Biden shut down the border to asylum seekers in June, encounters dropped over 50 percent.

Sheinbaum has said she will work with whoever wins the US presidential elections, even as both Democrats and Republicans have placed the scapegoating of migrants at the center of their presidential campaigns.

Trump has vowed to act as “dictator on day one” and deploy the military to round up and deport millions of migrants, including those under Humanitarian Parole and Temporary Protected Status. His campaign has spread the Hitlerite lie that Haitian migrants in Springfield, Ohio, are eating people’s dogs and cats and that masses of “non-citizens” are voting in the elections. Trump has threatened to impose massive tariffs on cars assembled in Mexico and to invade US imperialism’s oppressed neighbor, ostensibly to fight the cartels against the will of the Mexican government.

Vice President and Democratic presidential candidate Kamala Harris responded to the fascist Republican campaign against migrants by visiting the border in Arizona last Friday to promise to try again to push through what she called “the strongest border security bill,” which increases funding for the Border Patrol, further limits access to asylum requests and effectively grants authority to shut down the border.

The lives of migrant workers, including the millions of Mexican migrants and their families in the United States are regarded as merely a “bargaining chip” for Sheinbaum in negotiating with US imperialism for a larger share of the profits to go to the Mexican ruling class from the super-exploitation of the working class in Mexico. The threat of a fascistic dictatorship in Washington overseeing the mass detention of migrants and worse has brought about no change in course for Sheinbaum.