When Roger Mahony was about 12, law officers raided his father's poultry processing plant in the San Fernando Valley. They were searching for illegal aliens. "I will never forget them bursting through the doors," he recently told the Washington Post. "I was terrified by it. And I thought, 'These poor people; they're here making a living supporting their families."' Now, as Cardinal Mahony, leader of the 5 million Catholics (75 percent Latino) in the Los Angeles archdiocese, he is mounting a crusade on behalf of illegal immigrants, and is asking Catholics to express solidarity with them through prayer and fasting....