Feds May Sue Arizona Over Immigration Law Justice Department prepares to block state law By Rob Quinn, Newser Staff Posted Apr 29, 2010 4:00 AM CDT 32 comments Comments A man waits in a line at the border to legally cross into Arizona from Nogales, Mexico. (AP Photo/Gregory Bull) (Newser) – The Obama administration is considering taking the rare—and potentially explosive—step of challenging Arizona's immigration law in court. The government may sue the state over the law as the Justice Department examines ways to block the statute before it takes effect this summer, officials tell the Washington Post. Experts say any legal challenge from the federal government will likely center on the "preemption" doctrine, with lawyers arguing that Arizona is intruding on the federal government's responsibility for immigration enforcement. Challenging the law is likely to energize the Democratic base, analysts say, but it's certain to draw a fierce backlash from the right.