From the moment the Arizona legislature passed a misguided anti-immigration law, it was clear the plan was headed for a high-stakes legal challenge. The federal government's lawsuit filed last week should be the beginning of the end of a bad law aimed at fixing a legitimate problem.

The federal government's ineffective approach to illegal border crossings and the problems that come with it prompted Arizona to pass the bill. But one wrong does not justify another.

Arizona's overbearing legislation requires law enforcement officers, while enforcing other laws, to question an individual's immigration status if there is reason to believe the person is in the U.S. illegally. As part of the new rules, it is a crime for legal immigrants not to carry immigration paperwork.

Few admit this directly but it will be almost impossible to enforce the law without picking on brown-skinned Latino people. Even though Gov. Jan Brewer issued an executive order to law enforcement to enforce the new rules without racial profiling, that is not easy to do. The abrupt force of the law will come down on Mexicans living in Arizona — legal or otherwise.

Five other states are eyeing similar action, which further substantiates the need for federal intervention. The Arizona law invites a potpourri of immigration policies. The lawsuit focuses on the Supremacy Clause of the U.S. Constitution — the point being that federal laws override state laws. Our already tortured approach to immigration will become more incoherent with a variety of different laws in various states.

Currently, law officers around the country may check on immigration status of those they stop or arrest. The new law, supposed to take effect July 29, requires a check.

The Obama administration must tackle border security and America's own role in illegal immigration. This matter cries out for competent leadership, with the long-term goal of an immigration system that both cinches up the borders and provides certain workers a legal route toward citizenship

It makes no sense to have Arizona law enforcement officers stopping people because of the color of their skin and other states hatching willy-nilly methods of enforcing immigration rules.

The law must be struck down. The federal government should move to give states managing a host of problems associated with illegal immigration some relief and give a break to immigrants seeking a purposeful path to citizenship.