Immigration and Federalism

The Constitution states that the federal government should handle immigration while the states deal with the consequences of immigration. Because of this, many states such as Arizona have passed their own laws supplementing national laws on immigration, which is totally constitutional. The most recent law that Arizona has passed pertaining to immigration, sb1070, requires illegal aliens to carry their documentation with them at all times and allows police to question people that look suspicious. This law's passage is completely within Arizona's rights because of the Federalist views reflected in the Constitution.
However, Obama wants to interfere with this state law because his administration does not believe in what this law enforces (link to more info). He needs to remind himself what federalism is, and remember that he should not enact legislation against state laws just because he disagrees with them.