The U.S. Supreme Court has ruled that only the federal government, not states, holds responsibility for enforcing immigration laws. The invalidated provisions of Arizona law, SB 1070, passed two years ago, would have allowed authorities to arrest undocumented immigrants for looking for jobs and for not carrying registration documents. The other part of the law, which directs police to check the immigration status of individuals they suspect are in the country illegally when they make lawful stops for other reasons, is still in effect and will soon be enforced. Although President Obama said he was pleased by the ruling, he remained concerned “about the practical impact” of the Arizona provision that allows local law officers to make immigration checks.
http://articles.latimes.com/2012/jun/25/nation/la-na-court-immigration-20120626