On Wednesday, October 21, 2009, the New York Times Bay Area Blog invited Professor Rose Cuison Villazor to express her views on the recently amended confidentiality or "sanctuary" policy of the City of San Francisco. In it, she wrote:

The bedrock principle that immigration law is the exclusive province of the federal government will shape the analysis of whether San Francisco’s ordinance is valid. San Francisco’s ordinance highlights an ongoing debate about whether there is room within immigration law for states and local laws that directly or indirectly affect immigrants. Recognizing that immigration power rests with the federal government, courts have long held that state and local measures that have attempted to regulate immigration law were preempted by federal law. Thus, courts have deemed as preempted both “anti-immigrant” laws (such as the Hazleton, Pennsylvania’s housing ban on undocumented immigrants) and laws that are “protective” of unauthorized immigrants (such as New York City’s former confidentiality policy). Seen from the perspective of federalism principles, San Francisco’s ordinance is laudable but may rest on precarious grounds.