Edit: here's an interesting article on Lew Rockwell by Christopher Manion which attempts to explain why 30 million Americans identify themselves as former Catholics. Archbishop Gomez, himself, has no answer as to whether or not opposition to Amnesty is a sin, for he appears to have nothing but contempt for a large portion of his flock.
[Lew Rockwell] That is certainly what Los Angeles Archbishop José Gomez tells them. He is the point man among American bishops for open borders, mass immigration, and amnesty. Born in Monterrey, Mexico, he has never publicly disagreed with the views of the Mexican government and, alas, of his fellow Mexican bishops, when they condemn the United States. He does not defend Americans against their slanders, even though he knows that the leftist Masonic unigovernment of Mexico has always blamed the United States for its own rapacious exploitation of its people.
Taking a page from Lord Peter Bauer, the swaggering Junta tyrants always blame the United States: “Our poverty is your fault!”
In recent days, three Catholic priests have been murdered in Mexico. I have written Archbishop Gomez requesting that he provide any public comment he might have made regarding these horrific crimes and their possible causes; so far I have had no response. I have also asked Archbishop Gomez a simple question: are faithful Catholics bound by Church law to embrace your opinions regarding amnesty for illegal aliens with the same “religious submission of mind” that we are to embrace and follow the church’s moral teachings on sex and marriage?” (Viz. Can. 753)