Many people in Washington seem to be talking about the prospect of the president unilaterally legalizing the status of several million people who entered the country illegally as though it were just another political question. But if reports about the nature of the executive action he is contemplating are right, it would be by far the most blatant and explosive provocation in the administration’s assault on the separation of powers, and could well be the most extreme act of executive overreach ever attempted by an American president in peacetime....In one sense, the approach the president is said to be contemplating does fit into a pattern of his use of executive power. That pattern involves taking provocative executive actions on sensitive, divisive issues to isolate people he detests, knowing it will invite a sharp response, and then using the response to scare his own base voters into thinking they are under assault when in fact they are on the offensive. That’s how moving to compel nuns to buy contraception and abortive drugs for their employees became “they’re trying to take away your birth control.” This strategy needlessly divides the country and brings out the worst instincts of people on all sides, but it has obvious benefits for the administration and its allies.
Hot Air has an interesting (and grim) collection of other reflections on the president's possible power grab.