Former Deputy CIA Director Michael Morell testifies before the House Select Intelligence Committee April 2, 2014 in Washington, DC. (Photo by Win McNamee/Getty Images)

Perhaps the chief remaining mystery about Benghazi is why Republicans are still harping on it 19 months after the attack — and why they have been so willing to attack career diplomats, military officers and intelligence officials in their jihad against the Obama administration.

The latest official to be caught in the Benghazi shredder is Michael Morell, former deputy director of the Central Intelligence Agency. Sen. Lindsey Graham (R-S.C.) has charged that Morell “lied” about his role in crafting the famous talking points, and Sen. John McCain (R-Ariz.) has claimed Morell “compromise[d]” his “oath of office” in the hope of getting a promotion to CIA director. Those are serious allegations, even if often made in the Benghazi echo chamber of Fox News.

Morell responded Wednesday by doing something unusual in Washington: He answered the charges in open testimony to the House Intelligence Committee. That may only expose him to further assault — there is no winning battles like this in today’s political climate — but it was novel to see someone push back against personal attack.

Previous hit-and-run victims of the GOP’s Benghazi campaign have included retired Adm. Mike Mullen and former ambassador Thomas Pickering. A report last September by Rep. Darrell Issa’s House Committee on Oversight and Reform questioned “the independence and integrity of the review” conducted by the Accountability Review Board headed by Mullen and Pickering. Issa presented no evidence to back up his smear against a former chairman of the Joint Chiefs of Staff and a former ambassador to six countries.

Morell addressed what his critics have argued were damning points. He explained why the famous talking points continued to say the Benghazi assault emerged from a “protest” even though the CIA station chief in Tripoli had said the opposite in a cable two days before: At that point, the agency’s analysts still thought wrongly that it was a protest, and Morell went with the analysts. And he rebutted Graham’s charge that he deliberately lied in telling the senator incorrectly that the FBI had requested deletion of a reference to al-Qaeda from the talking points. Morell said he made a mistake about the FBI, which had objected to another reference about “Islamic extremists,” and he corrected the record three hours later.

Morrell concedes that he and the analysts made mistakes — and he’s right. The whole talking points exercise was a bureaucratic mess of turf-protection and backside-covering. And he is putting it mildly when he says his final edited version “was not an example of the CIA’s best work,” that it involved too many public affairs people, and that the agency shouldn’t have been writing talking points in the first place.

It’s also worth mulling that the CIA station chief in Tripoli got it right, quickly, about the nature of the Benghazi attack when the analysts back at headquarters were wrongly saying it involved protests outside the consulate, as opposed to an attack by al-Qaeda-linked extremists. Often, the person on the ground does have a better feel for events than someone in an office in Langley — something that career analysts such as Morell are sometimes reluctant to accept.

Morell’s most intriguing comment, though, was about the role played by former CIA Director David Petraeus, who got the talking points saga rolling when he briefed the House Intelligence Committee on Benghazi and then promised a summary that members could use publicly. Petraeus wanted to cite warnings the agency had made about Libya prior to the Benghazi disaster that left four people dead. Initially, the director’s points were duly included, but Morell penciled them out.

“I saw the language as self-serving and defensive on the agency’s part,” Morell writes in his prepared testimony. “Here was a tragic event, and we were saying, ‘We told you so.’ This was wrong, in my view, and would have been seen as an attempt to make the CIA look good and shift any possible blame for failing to see the risk of an attack from the agency to the State Department.” That is a rare public shot at a former CIA director from a former deputy.

The real significance of Morell’s testimony was that he directly rebutted the GOP charge that the CIA, in concert with the White House, “cooked the books” on Benghazi with manufactured talking points that Morell knew were wrong, and then covered it up. To continue their Benghazi conspiracy-mongering, Republicans will now have to continue arguing that Morell and hundreds of others are lying. I suspect they’ll double down, once more, rather than concede that this is a losing issue that has been grotesquely blown out of proportion.