Heather McDonald has written a long but ultimately unsatisfying jeremiad for City Journal. She does a very thorough job of citing example after example of problems resulting from an influx of illegals but she draws no attention to the fact that all of her examples are drawn from a very small geographic area and are the proximate result of a decision made by the Los Angeles City Council which instructed the LAPD to develop what became known as Special Order 40. McDonald did a better job on "root causes" in this 2004 City Journal article which explains the political dynamic a bit more completely. Her paragraph on Giuliani's fight to protect illegals is rather entertaining - and very good ammo for his opponents in the primaries.
It is impossible to insist that the Feds "enforce the law" while local and state governments do their damnedest to resist enforcement. Georgia and Arizona are both doing what is necessary to discourage illegals but as long as southern California remains an illegal migrant magnet - with "amnesty" and court mandated benefits, the national problem cannot begin to be solved.