Obama vs Arizona

The Obama administration is suing to stop the Arizona immigration law. As reported by ABC:

The filing makes no assertion that the law is discriminatory or risks being applied in a discriminatory fashion, as the president and other officials said they feared would be the case. Interestingly, this suit makes no civil rights charges against the Arizona law.

They are centering the case on a claim of pre-emption, that basically the state's action would prevent effective enforcement of immigration law at the Federal level. Why this is not the punchline in a late-night monologue is not explained. To be clear, the Arizona law explicitly makes EXACTLY violation of Federal immigration law a state trespass violation. It's the opposite of pre-emption.

By the Obama administration logic in the case, sanctuary cities should subject to lawsuits . But it's not about logic, it's about stopping the enforcement of immigration law. Obama's DOJ is not suing because Arizona is stopping imigration law enforcement, they are suing because Arizona IS enforcing it.

Arizona's response: