How can we describe the character of the mestizo in Greene's The Power and the Glory?

The mestizo, a word once used to describe people of mixed
European and Native American ancestry, is a symbolic character that is not fully
developed. Graham Greene developed the mestizo only so far as to fulfill his symbolic
function so he remains a flat character who never develops and so is static. His
symbolic function is that of representing the Judas figure in the whisky priest's
life.

The encounters between the whiskey priest and the mestizo
provide opportunities for the whiskey priest to attain or reclaim some higher purpose in
his own call to the priesthood--he can step outside of his own barriers of guilt and
inadequacy and do something for someone in need.

The mestizo, the
recipient of the whisky priest's kindnesses, is belligerent and ungrateful and turns his
back on the priest by tracking across the border. While he is thankless and heartless,
he is greedy and asks the captured priest to pray for him. The mestizo thus symbolizes
the betraying Judas figure in the story. Nonetheless, he is not wholly without sympathy
because we see him through the priest's eyes while he ministers to the mestizo with
kindness; we see him as the priest visualizes him:

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When you visualized a man or woman carefully,
you could always begin to feel pity .... When you saw the lines at the corners of the
eyes, the shape of the mouth, .... Hate was just a failure of the
imagination.