Actually, this is in and of itself a very conservative position. Going all the way back to before Marbury.
I believe A. Lincoln advocated something like it for the Dred Scott case.
Should Obama do it, it will create a very interesting precedent that say a Walker or Cruz administration could use for all sorts of things.
Also, I’m not sure Lincoln counts as a conservative — after all, he really started the move from the Founders’ federal system to what we have now, essentially a unitary state with the “states” being somewhat autonomous provinces.