From our favorite Earth-Bound Misfit:
It’s the job of the Justice Department to defend the constitutionality of the laws that have been enacted. Congress enacts the law, the Executive enforces and defends the law, and the Court says what the law is. If any president disagrees with the law, the proper route is to go to Congress to change the law, not to slime its way into court and attack the law there.
Worse, how are we, as a people, supposed to know what conduct is illegal and what isn’t if the enforcement of the law is openly acknowledged to be up to the whims of the Executive branch? If ignorance of the law is no defense to breaking it, now we have to know what laws are effectively voided because the prosecutors are going to look the other way?