<P> On September 5, 2007, Department of Homeland Security Secretary Michael Chertoff told a House committee that he certainly wouldn't tolerate interference by sanctuary cities that would block his "Basic Pilot Program" that requires employers to validate the legal status of their workers . "We're exploring our legal options . I intend to take as vigorous legal action as the law allows to prevent that from happening, prevent that kind of interference ." </P> <P> On January 25, 2017 President Donald Trump signed Executive Order 13768 directing the Secretary of Homeland Security and Attorney General to defund sanctuary jurisdictions that refuse to comply with federal immigration law . He also ordered the Department of Homeland Security to begin issuing weekly public reports that include "a comprehensive list of criminal actions committed by aliens and any jurisdiction that ignored or otherwise failed to honor any detainers with respect to such aliens ." Ilya Somin, Professor of Law at George Mason University, has argued that Trump's withholding of federal funding would be unconstitutional: "Trump and future presidents could use (the executive order) to seriously undermine constitutional federalism by forcing dissenting cities and states to obey presidential dictates, even without authorization from Congress . The circumvention of Congress makes the order a threat to separation of powers, as well ." On April 25, 2017, U.S. District Judge William Orrick issued a nationwide preliminary injunction halting this executive order . The injunction was made permanent on November 20, 2017, when Judge Orrick ruled that section 9 (a) of the order was "unconstitutional on its face". The judgment concluded that the order violates "the separation of powers doctrine and deprives (the plaintiffs) of their Tenth and Fifth Amendment rights ." </P> <P> Whether federal or local government has jurisdiction to detain and deport illegal immigrants is a tricky and unsettled issue, because the U.S. Constitution does not provide a clear answer . Both federal and local government offer arguments to defend their authority . The issue of jurisdiction has been vigorously debated dating back to the Alien Act of 1798 . Opponents of local level policing tend to use the Naturalization Clause and the Migration clause in the Constitution as textual confirmation of federal power . Because the Supremacy Clause is generally interpreted to mean that federal law takes priority over state law, the U.S. Supreme Court in the majority of cases has ruled in favor of the federal government . Certain states have been affected by illegal immigration more than others and have attempted to pass legislation that limits access by undocumented immigrants to public benefits . A notable case was Arizona's SB 1070 law, which was passed in 2010 and struck down in 2012 by the Supreme Court as unconstitutional . </P> <P> States like Arizona, Texas and Nevada justify their aggressive actions as a result of insufficient efforts by the federal government to address issues like use of schools and hospitals by illegal immigrants and changes to the cultural landscape--impacts that are most visible on a local level . Ambiguity and confusion over jurisdiction is one of the reasons why local and state policies for and against sanctuary cities vary widely depending on location in the country . </P>

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