Ed Whelan screeches at E. J. Dionne, and it's all very drama like the climax of a noir film.
Further, far from “questioning President Obama’s decision,” Scalia is expressly agnostic on it, as language that Dionne quotes but doesn’t grasp (“The president has said that the new program is ‘the right thing to do’…. Perhaps it is, though Arizona may not think so”) shows. Scalia’s point (which, again, Dionne quotes but doesn’t grasp) is that what matters is whether Arizona’s law conflicts with federal immigration law, not whether it conflicts with the Obama administration’s enforcement priorities. There may well be reasonable grounds for contesting this legal proposition, but Dionne’s contention that Scalia was being “blatantly political” in making it is woefully ill-informed.
When you're down to the "let's pretend to not understand sarcasm" defense, it's only because you don't know who, exactly, you need to blow.