My supposition is that he was referring to 18 USC 2384, Seditious Conspiracy, which reads as follows--and I've bolded the portion that could arguably apply to this factual situation:
If two or more persons in any State or Territory, or in any place subject to the jurisdiction of the United States, conspire to overthrow, put down, or to destroy by force the Government of the United States, or to levy war against them, or to oppose by force the authority thereof, or by force to prevent, hinder, or delay the execution of any law of the United States, or by force to seize, take, or possess any property of the United States contrary to the authority thereof, they shall each be fined under this title or imprisoned not more than twenty years, or both.
I think diGenova's argument is that Obama and the Intel Community were part of a conspiracy to "overthrow" the Government of the United States.
Obviously that argument has to address the meaning of "overthrow." My counter argument would be that the context appears to require that any seditious conspiracy must be a conspiracy to use physical force or--at a minimum--a credible threat to use physical force in some real sense. I believe the history of the use of our sedition laws bears out my interpretation.
Nevertheless, it seems to me that Obama was treading an exceedingly fine line. It's not much of a step from urging the violation of key intel officials' oaths of office by withholding national security information from the Commander in Chief regarding the purported actions of a hostile foreign power to the possibility of advocating mutiny in the armed forces. And that definitely would be a seditious conspiracy.
In that regard, it's also important to bear in mind diGenova's brief remarks about the FISC. He points out that both Chief Judges--Collyer and Boasberg--who have examined these matters have accused the Obama administration's intel agencies of gross violations of law. One could argue that this is, at least metaphorically, violence or "force." More on FISA below.
Andy McCarthy's interview is also quite informative. He deals with matters we've discussed here previously, especially the idea of "The Wall" between counterintelligence investigations and criminal investigations that was in place until the Patriot Act came along. McCarthy gets into the implications of tearing down that wall--something that he favored at the time but now regards as misguided.
He also makes the interesting observation that it would have been very difficult--really, impossible--for the FBI to have continued its investigation of Trump (because that's what was happening) if Trump had a "sophisticated intelligence actor like General Flynn" in place as NSA. Which, of course, raises the question: What about General McMaster, who was NSA from 2/20/17 to 4/9/18?
I was also very pleased to learn that McCarthy agrees with me regarding the FISC--the FISA court regime for handling applications under FISA. He rightly observes that the work of the FISC isn't really judicial branch work and that the FISC judges are basically at the mercy of the FBI and DoJ--the judges have no practical way of riding herd on the FBI and DoJ. Like me, McCarthy urges that oversight of this sort is properly the work of Congress, and he points out that the FBI was clearly not worried about pulling the wool over the FISC's eyes--they went back to the FISC with the same trashy Carter Page application "again, and again, and again." He concludes by stating that this type of oversight is political in nature, not judicial--which is exactly right.
Listen to both interviews HERE.