In 1938, Greene traveled through Mexico in order to write a chronicle about the persecution of the Catholic Church under a stridently atheistic Mexican regime. Anti-clericalism had been violently present in Mexico for several decades, most infamously under the presidency of Plutarco Elias Calles (1924-28). Mexico had suffered through many years of social unrest and revolution in the first couple decades of the 20th century. In 1917, a degree of stability was restored in a national constitution. The terms of the constitution mandated that all education must be strictly secular, outlawed monastic orders, limited the practice of public worship, and made churches register with the state while limiting their right to own property. Further, members of the Catholic clergy were prohibited from wearing clerical vestments, voting in government elections, and from making any public comments about government policy to the press or their congregants. The persecution of Catholics was especially severe in the state of Tabasco under Governor Tomás Garrido Canabal (1920-24, 31-34). Churches in Tabasco were closed and priests were forced to marry or flee at risk of their lives. Canabal also ordered crosses removed from grave stones, suppressed the word “adios” (to God), and threatened clergy members with imprisonment and death. The governor's atheism was so exaggerated that he named his children Lenin and Zoila Libertad (he also had a nephew named Lucifer), and chose to call his farm animals "God," "Pope," "Mary," and "Jesus." It is also claimed that he encouraged a local satirical play which featured a stud bull being paraded around called “the bishop” and an ass labeled “the pope.”

This is the Mexico which provides the setting for The Power and the Glory. In many ways, the Mexican repression of the Church is a violent parallel to the more “scientific” and ”peaceful” ecclesial repression taking place in the former domain of Christendom. Mexico, the colonial child of Europe, merely carried out the same anti-clerical agenda of the modernists in a more overt, childish way.