'... President Obama ... the ultimate enforcer of the law' Um what?
That's the role of the executive branch, and President Obama is the head of the executive branch. It's weird to see it phrased that way, but it's not incorrect.
If you read court decisions where a law is criticized by a judge or justice as unjust or unfair (but not necessarily unconstitutional), they never say that prosecutors should stop bringing such cases to court; they say that changing the law will require Congress to act.
To take a current example of the dichotomy, the Obama administration has filed a brief with the Supreme Court asking it to overturn DOMA (Defense of Marriage Act), as it's the administration's belief that the law is unconstitutional - but in the meantime, the administration is still implementing DOMA as written, because until the SC rules against it (if they do) it remains the law of the land. If two married gay people file a joint tax return, the IRS will send it back with an apologetic letter and tell them they have to file separately and so on.