Good article by Peter Schrag in The New Republic on how federal inaction has prompted state activism on immigration, focusing on California. There's nothing exactly new, but the argument is well articulated. This quote is perfect:
It’s long been obvious that, as it’s currently designed, the law can’t work
And that's the bottom line. Making laws that cannot be enforced is irrational from a policy perspective, even if believed to be useful in political terms. Either way, the result is an endless loop of law-breaking and complaints of law-breaking that create new unenforceable laws that expand the scope of law-breaking.
He also nails this:
If nothing else, it would be a challenge to Obama, who’s spent the past three years dithering between brave rhetoric about bringing the undocumented out of the shadows and, until recently at least, presiding over an enforcement regime—including a record 400,000 deportations in the past fiscal year—that’s tougher than anything under George W. Bush. The deportations almost certainly cut into the enthusiastic political support from Latinos and other backers of legalization that Obama enjoyed in 2008. COPA and the California laws favoring illegal aliens that preceded it indicate that in the face of Washington’s inaction on immigration individual states could go left as well as right. More important, it makes the need for federal action all the more urgent.
I've argued along similar lines as well.