“I can’t imagine any circumstance under which the Executive Branch of the federal government would have the authority to make a state overturn a state law.”
You must remember that we live in Obama’s America where from simply reading this story it is obvious that Obama is handing down judicial decisions.
I don't doubt that Obama would make such an order. But it's impossible for me to imagine that the state of Oklahoma would recognize such a blatantly invalid "order" as having any legal weight at all.