So what he's saying is, yes!
Rod Rosenstein must think that people (including his interrogators in Congress) are really stupid. I mean, baseline, knuckle-dragging idiots. When asked if anyone spied on the Trump campaign or its personnel by Rep. Ron DeSantis, his response was, "“As I said, congressman, appreciate the — I understand your interest, I’m not permitted to discuss classified information."
By definition - under the framework of basic logic - to deny answering this question on the basis of confidentiality, is an admission that there is information regarding spying on the Trump campaign/personnel. It's simple. If there was a clear answer that no one spied on Team Trump, there would be nothing classified in sharing this information. Think about it. If they had a clear answer of "No", they would just say so. A husband accused of his wife by infidelity, would not hesitate to truthfully share the fact that he had not cheated on her.
Perhaps the 4D Chess crowd might suggest that Rosenstein was purposely answering in this manner because he secretly supports Trump and wants to telegraph an answer that there was indeed spying. I won't speculate on that but I will say that his answer today did certainly telegraph the answer that the DOJ/FBI were certainly doing something sneaky and wrong that they would rather not discuss.
Just think about it...
CW