Do you seriously think that any Republican governors would fail to raise a major (and loud) stink if Obama were to infringe upon their own powers. Governors guard their powers zealously.
In answer to that, he's been usurping state powers with EOs for 3-1/2 years. Also, the congress has been doing its share of it. I don't see that what protesting I've heard has done much good.
Specifically, though, I do recall him doing something to peel away another layer of state control regarding the NG. If I have time, maybe I can find it. My post #33 does add a little more information on the whole subject.