I point readers to the following article:

Judicial Watch - Fighting corruption & promoting transparency in government through public education and use of the Freedom of Information Act.

Posted on:                          Tuesday, July 06, 2010 10:22 AM
Author:                                Judicial Watch Blog
Subject:                               Illegal Immigrants Cost U.S. Taxpayers $113 Billion Annually .

On the heels of a new study that reveals illegal aliens cost U.S. taxpayers $113 billion a year, the Obama Administration has filed a lawsuit challenging Arizona’s measure to curb illegal immigration.

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Apparently the US Justice Department is arguing that the Constitution provides responsibility for enforcement of immigration laws to reside with the federal government only and that Arizona "..illegally intrudes on the federal government’s duties to enforce immigration laws."

Following Eric Holder's and Barack Obama's logic:

• the US Constitution provides for the US government to collect an income tax.   Does this make all state income tax laws then unconstitutional?
• it is the responsibility of the FBI and the Treasury Department to protect this country against counterfeiting of US Currency.  Shall it be unconstitutional from this point forward for state and local law enforcement to assist federal law enforcement in this effort?
• it is the responsibility of the FBI and Secret Service to protect the President.  Should local law enforcement never again assist in the protection of the president when he comes to Phoenix, to Denver, to Austin?  
• officer JD Tippit sacrificed his life unnecessarily and the Dallas police had no business arresting or even pursuing Lee Harvey Oswald because the murder of the president was a federal crime.

The Arizona law mirrors federal law.  There are no new penalties.  There are no new restrictions on immigration beyond those already incorporated in federal law.  The law merely authorizes the local police to assist the federal government and provides a means for them to forward those apprehended to the appropriate federal agency.  The law even states that no one may be asked their immigration status unless the police is involved in some other legal action that involves a suspected illegal immigrant.