MEXICO CITY —

The two appear an unlikely political pair: he a shopkeeper’s son from rural southern Mexico, she a globally recognized scientist from the capital.

He is outgoing and folksy, a larger-than-life figure comfortable pressing the flesh and mingling with crowds. Her reserved manner and lack of charisma feed the notion that she is distant and arrogant.

When it comes to their politics, however, it is difficult to distinguish Andrés Manuel López Obrador and Claudia Sheinbaum, whose long history together has uniquely positioned her to succeed him as the country’s president next year.

Sheinbaum, who would be the first woman to hold the job, has cast her candidacy as a victory for feminism.

“Mexico is no longer written with the M of machismo,” she told tens of thousands of supporters gathered in the capital this month as she resigned from her job as Mexico City mayor to formally enter the race for president. “But rather M for mother, for mujer” — woman.

But her anointment by López Obrador — who is widely known as AMLO — and her wholesale adoption of his policies, leftist ideology and even some of his speech patterns have led some pundits to wonder whether she is her own person.

“Claudia is not questioned for being a woman, but rather for mimicking a man and transforming herself to please AMLO,” tweeted Denise Dresser, a professor of political science at Autonomous Technological Institute of Mexico and fierce critic of the populist president. “Nothing is more contrary to the agenda of autonomy/feminine empowerment that marks a new generation of women.”

The 60-year-old Sheinbaum would also be the first president from Mexico’s small Jewish community.

Though she spent two decades in academia before starting her political career, she comes from a tradition of political engagement.