The Supreme Court Monday critically wounded Arizona’s immigration law, striking down three key provisions and sending the message that federal law trumps state law on immigration. The court should have gone one step further and killed the law altogether by striking down the noxious “show me your papers” requirement, but even there it left the measure pretty much toothless and left open the door for further litigation.

The ruling is generally a victory for reasonable immigration policy, the Obama administration and many in the immigrant community. It also should mean that immigration policy and immigration reform need to be settled in the halls of Congress, not in the halls of state capitols. Congress and the Obama administration need to get to work on that.

Arizona’s law was the result of understandable frustration with lack of change at the federal level, a frustration that’s felt in a number of states, including Wisconsin. Arizona’s answer was to try to impose a harsh crackdown on illegal immigrants and impose a law that superseded federal law. But the Constitution is clear; states do not have the authority to supersede or undermine federal law.