The United States Justice Department filed a suit against Arizona’s new immigration law today. According to the Wall Street Journal, the Justice Department will sue on the grounds that Arizona’s new immigration law illegally intrudes on federal prerogatives and violates the Constitution’s supremacy clause, which states that federal law trumps state statutes, legally referred to as “preemption.” Justice Department officials believe that enforcing immigration laws is a federal responsibility, according to the Washington Post. The new law allows law enforcement officials in Arizona to request proof of legal immigration, residency, or citizenship of anyone they suspect might be an illegal immigrant. Once the new law is enacted later this month, many of the people Arizona officials detain will be sent to federal immigration agencies, which may interfere with the regular operations of the agencies. Secretary of State Hillary Clinton was the first to hint that the federal government would file a suit against the Arizona law last month. President Obama spoke out against the Arizona law in his address to Congress last week, stating, “As other states and localities go their own ways, we face the prospect that different rules for immigration will apply in different parts of the country, a patchwork of local immigration rules where we all know one clear national standard is needed,” according to the Associated Press. Attorney General Eric H. Holder Jr. and many civil rights groups have also publicly condemned the law. At least five other lawsuits have been filed against the Arizona law. The current lawsuit could delay the law from going into effect.