I too agree . . . if you don't like the law, change it. But, until then enforce it.
Police Officers have had to do the same thing for years, on a variety of unpopular issues.
He's on record as saying "I can't do that" regarding executive ordered amnesty.
I think this might really be just a Left vs Right draw play...knowing it'll never really stick.
He did it, so when the Right rears up and challenges it - he can say to voters
"Hey, I(we) tried to help you out.
But, the Right blocked me. I(we) really tried.
See how evil they are !!!"
He gets credit for trying and the Right gets the black eye.
This issue and the "Fast & Furious" contest are both distractions from other things. He's all about diverting attention.