Religion has been the electrified 'third rail' of Mexican politics since anticlerical laws in the 1920s sparked a bloody uprising by Catholics in which thousands died.
But this week, front-running presidential candidate AndrÃs Manuel LÃpez Obrador not only brushed that third rail - as he and others have in the past - he grabbed it firmly with both hands and held on.
He pledged to seek "not only material well-being, but the well-being of the soul" if elected in the July 1 elections, adding, "There are many who have said Christ is love."
LÃpez Obrador spoke Tuesday at a ceremony to accept the nomination of the tiny Social Encounter Party, which is heavily influenced by evangelical churches.
LÃpez Obrador's main campaign theme has long been the fight against corruption, and he has argued that a "moral regeneration" is the only way to clean the country up. He has also long been said to possess a kind of messianic zeal and confidence in his own moral compass.
LÃpez Obrador has previously described himself as a Christian "in the broad sense," and has used quasi-religious rhetoric, like describing corruption as a "civic sin".
"It is indispensable that we start a new current of thought that promotes a moral paradigm, love for one's family, one's neighbour, for nature, for our country.
"I know this is a very polemical issue," Lopez Obrador said. "Those who think this topic doesn't belong in politics have forgotten that the highest goal of politics is to achieve love.
"I do not believe this contradicts my theory of a secular state," he continued, quoting the biblical book of Matthew: "Render unto Caesar the things that are Caesar's, and unto God the things that are God's."
The separation of church and state is closely watched in Mexico, where many people remain suspicious of a church that held a government-enforced monopoly of faith for more than three centuries. Mexico re-established relations with the Vatican only in 1992.
President Vicente Fox, a practising Catholic, raised eyebrows in Mexico by kissing the pope's ring when John Paul II arrived in Mexico in 2002.