Twenty-three years ago, Eva Tinoco left everything she had and most everyone she knew for the sake of her children. Neither fear nor immigration laws were on her mind when she left her little Mexican village bound for the United States, she said. After entering the country illegally in 1981, she and her six children were among the 2.7 million immigrants who became lawful residents under the Immigration Reform and Control Act of 1986. The law was supposed to be the solution to growing concerns about illegal immigration. It proposed a two-pronged approach: First, legalizing immigrants who were already in...