MEXICO CITY - She rose to the podium and cast her eyes skyward. The mayor of Monterrey then entrusted her Mexican city to God and Jesus Christ as the crowd around her cheered.

"I open the doors of this city to God as the maximum authority," Mayor Margarita Arellanes said. "I recognize that without his presence and his help, we cannot have real success."

Whether a sign of desperation for how dire things are in northern Mexico, which is plagued by drug violence, or simply a profession of faith, Arellanes' weekend speech has rankled many in this country where the separation of church and state is a founding principle - one that helped spark a violent uprising a century ago.

One columnist called her the new Mexican Sarah Palin - alluding, he explained, to a relatively inexperienced politician who isn't shy about wearing her religion on her sleeve, like the former U.S. vice presidential candidate.

Leftist congressmen in Mexico City suggested Arellanes should be investigated and maybe even brought up on charges. A host of academics and legal experts quickly listed the articles of the Mexican Constitution that she may have violated. Even some from her own conservative National Action Party, or PAN, complained, but perhaps because her pious pledge came at an event organized by evangelical churches, not Roman Catholic ones.

"She should have been more careful," said PAN Sen. Luisa Maria Calderón, sister to former President Felipe Calderón.

Monterrey's leading independent human-rights organization, which is run by a nun, said turning the city over to Jesus was "undemocratic and unrepublican."

Arellanes, 36, is sticking to her convictions, saying she broke no laws because she spoke as a private person, not the mayor of Mexico's wealthiest and third-largest city. That distinction, however, seemed to have been missed by most who either heard the mayor speak or have since watched her presentation on YouTube.

What apparently irks many here is that displays of religion have been steadily creeping into public life in recent years, which some Mexicans see as an erosion of the secular identity of the state.