The feds claim that Arizona oversteps its bounds because its law "pursues only one goal--'attrition' "--at the expense of others, such as concentrating enforcement on the most dangerous aliens, protecting the rights of asylum seekers, and maintaining amity with Mexico and other foreign countries. The real issue in this case is not whether the federal government has the power to pre-empt Arizona's immigration law, as it asserts in the lawsuit. It unquestionably does. The question is whether Washington has properly exercised that power.