MEXICO CITY — Under a banner declaring "ours is a question of dignity," defeated presidential candidate Andres Manuel Lopez Obrador announced Sunday in this city's massive Zocalo main square that he was withdrawing from the leftist parties he has long dominated while also launching a campaign of peaceful resistance to the newly elected government.
Lopez Obrador, who came in second in the July presidential vote, said during a rally that he would not recognize the official results that named Enrique Peña Nieto of the Institutional Revolutionary Party, or PRI, as the winner.
"In this new phase of my life, I am going to dedicate my imagination and work for the cause of transforming Mexico," Lopez Obrador said.
He said he was leaving the mainstream leftist coalition that had backed his candidacy and would lead a "movement" that he formed several years ago called Morena, or the Movement for National Regeneration, which is dedicated to social and political change. He would decide at a later date, he said, whether to formally constitute Morena as a political party.
Lopez Obrador insisted that his departure from the Democratic Revolution Party, or PRD, and its partner factions was on amicable terms and "not a rupture."
On the face of it, his actions might be interpreted as yet another fissure in the notoriously fragmented left, divisions that have played at least a minor role in preventing the PRD and allies from obtaining wider national power, including the presidency.
If Lopez Obrador does turn Morena into a political party, he could easily be its presidential candidate in elections in 2018, a challenge that would split the votes within the left and further erode its electability.
But his withdrawal also allows the mainstream left to proceed without a figure that was increasingly polemical. Lopez Obrador was at times erratic and confrontational on the campaign trail, and he alienated many of the more centrist voters whom he needed to win the election.
Many on the left have said they would have preferred a more moderate candidate, such as Mexico City Mayor Marcelo Ebrard, who could possibly have had a wider appeal that would have proved a more effective challenge to the PRI electoral powerhouse. But Lopez Obrador's following proved overwhelming, and he won the party's nomination.
Jesus Ortega, former national chairman of the PRD, said that although he hated to lose Lopez Obrador, his departure could "end the political schizophrenia" that has dogged the left, a reference to tensions between the moderate and more radical factions.
"What we want now is that the left, and especially the PRD, have a cohesive vision of the reality of the country, of how to confront it and, above all, a common vision of how to confront the political and social crisis our country is living," Ortega said in a news conference a day ahead of Sunday's rally.
Still, the left has few leaders with the charisma of Lopez Obrador.
The meeting in the Zocalo was convened by Lopez Obrador a week ago, and the size of the turnout was considered an important test of his ability to galvanize a protest movement. Six years ago, when he also lost the presidential election — but by less than a percentage point — Lopez Obrador inspired hundreds of thousands of people to turn out into the streets, weeks of demonstrations that paralyzed Mexico City and roiled national politics.
It was difficult to come up with an accurate count of Sunday's crowd, but it was by all accounts far smaller than in the past.
The rally also served to announce a series of protest actions that the left will conduct, including street demonstrations timed to coincide with the inauguration of Peña Nieto on Dec. 1.
Lopez Obrador and his allies accuse the PRI of essentially buying the vote with gifts and over-the-top spending. But a court rejected the complaints and affirmed Peña Nieto's victory, which restores to the presidency the party that ruled Mexico for seven decades until falling to defeat in 2000.