Let the Arizona Law Stand, Then Wither THE United States Supreme Court is scheduled to hear arguments on Wednesday in Arizona v. United States, the Obama administration's challenge to Arizona's immigration law, known as S.B. 1070. The law requires local law enforcement to make immigration-status determinations - traditionally the prerogative of the federal government - and to arrest people suspected of being undocumented. S.B. 1070 effectively makes undocumented status a crime under state law and penalizes unauthorized employment. Arizona is one of several states, including Alabama, Georgia, South Carolina and Indiana, that, frustrated by Congress's idling on immigration reform, have challenged federal authority by taking it upon themselves to devise draconian policies for undocumented immigrants. Alabama's law even requires schools to collect immigration-status data on their students. Such laws are misguided at best, mean-spirited and racially tainted at worst. The conventional wisdom among immigration advocates is that immigrant interests will be best served if the Supreme Court makes an example of Arizona's law by striking it down. But in the long run, immigrant interests will be better helped if the Supreme Court upholds S.B. 1070. Laws like Arizona's are such bad policy that, left to their own devices, they will die a natural death - and their supporters will suffer the political consequences. Undocumented immigrants may themselves be politically powerless, but they have powerful allies. In Alabama and Georgia, dismayed farmers have watched crops rot in the fields for want of immigrant labor. Arizona is estimated to have lost more than $140 million from convention cancellations made in protest. Even more important is the prospect of lost foreign investment. Caught in the net of Alabama's law in November was a German Mercedes-Benz executive, who left his passport at home while out for a drive and as a result found himself in a county jail. Mercedes has a plant in Tuscaloosa that employs thousands of Alabamians and adds many hundreds of millions of dollars to the state economy. That embarrassment will make the next foreign company think twice as it scouts out a location for a manufacturing facility in the United States. Even without such blunders, international human rights advocates, union organizers and shareholder activists are putting these laws on the corporate social-responsibility agenda. Earlier this month, opponents of Alabama's law traveled to Berlin to press the issue at Daimler's annual meeting. This is the kind of hassle that corporations hate. Why deal with Alabama or Arizona when you can build in North Carolina or Florida, states that have refrained from pursuing extreme anti-immigrant measures? Similar anti-immigrant laws are often introduced but rarely enacted, as corporate interests work quietly to kill or defang them. Mississippi became the latest state to refuse to follow in Arizona's footsteps when an illegal-immigration bill died in a State Senate committee earlier this month in the face of opposition from prominent local business groups. In those states that have enacted laws, there are moves to roll them back. The Alabama House of Representatives has approved a Republican-sponsored bill to soften its current law. At the local level, Riverside, N.J., repealed a similar ordinance following the exodus of an economically vibrant immigrant community. In other words, the problem will largely self-correct. But even to the extent that it doesn't, the courts should still refrain from overturning such laws. Judicial intervention risks generating its own backlash. If the Supreme Court strikes down S.B. 1070, anti-immigrant constituencies will redouble their efforts to enact tougher laws at the federal level. A cautionary tale here is California's Proposition 187, a punitive immigration law that was blocked by a federal court in 1994 before it went into effect. Two years later, undaunted supporters helped push through the harshest overhaul of federal immigration policy in decades. Even if some of these state immigration laws survive political, corporate and consumer opposition on the ground, it's better to have the scattered imposition of state laws than the blanket coverage of a federal measure. Other states and localities are welcoming immigrants, legal or not. That fact gets lost in the common indictment of state and local immigration measures as a "patchwork." One of federalism's core virtues is the possibility of competition among states. Competition in this context is likely to vindicate pro-immigrant policies. We should hold our noses and hope the Supreme Court lets S.B. 1070 stand, so we can watch it wither away on its own.