A large crowd that included Vice President Mike Pence and Ivanka Trump watched Saturday as Andres Manuel Lopez Obrador became the first leftist president in Mexico in 70 years.
Lopez Obrador, 65, vowed to fight crime and corruption during his inaugural speech to Congress at the Chamber of Deputies in Mexico City that kicked off his six-year term.
During his remarks, he pledged "a peaceful and orderly transition, but one that is deep and radical ... because we will end the corruption and impunity that prevent Mexico's rebirth."
He enters office having won a landslide election victory on promises to eradicate corruption, impose government austerity and greatly expand social programs and public investment, The Wall Street Journal reported Saturday.
Already Lopez Obrador faces two intractable problems: a caravan of Central American migrants camped out on the border seeking to apply for asylum in the U.S. and a rising homicide rate.
"We are going to govern for everyone, but we are going to give preference to the most impoverished and vulnerable," Lopez Obrador said. "For the good of all, the poor come first.'"
Lopez Obrador also personally thanked U.S. Vice President Mike Pence and President Donald Trump for the "respectful treatment" he has received from the U.S.
But Lopez Obrador was clear in blaming extreme market-oriented policies he calls neoliberalism for Mexico's problems.
"Mexico's crisis originated not only with the failure of the neoliberal policies applied over the last 36 years," he said in his inaugural speech, "but also in the prevalence of the filthiest corruption."
The rowdiest response from Congress came when Lopez Obrador pledged "not to persecute officials of past administrations," saying "revenge is not my strong suit."
Legislators responded by counting loudly to 43 — the number of students kidnapped and disappeared in September 2014 — to remind Lopez Obrador of his promise to establish a truth commission to find out what happened to the students, a pledge he repeated Saturday.
Prosecutors have said they were kidnapped by corrupt police and turned over to a drug gang that killed them and burned their bodies.
The Associated Press contributed to this report.