The more I ponder on Obama, the more I think he's a figurehead, a front-man for his backers.
I don't think he's stupid, far from it. Certainly his backers are long-term strategic thinkers, and Obama has plenty of very good tactically adept political types to help him.
Some, or even most of what he is doing, and plans to do may seem stupid, but only if you don't happen to share his value system, which is to say, the value system of his bosses.
Now, I can only guess at Obama's motivations, but I suspect that reverence for the Constitution and maintaining the position of the US as the world's pre-eminent power are not high priorities for him, and more importantly, his backers. It is they who call the tune, and Obama who calls out the marching orders to the rank-and-file.
Can't prove a word of it, of course, and YMMV. Some day, maybe years from know, we'll know the truth of it.