Having debased himself so thoroughly during the 2016 presidential campaign, Rudolph Giuliani has fallen far in public esteem since his heyday as “America’s Mayor,” the unquestionable hero of 9/11. And now that he has returned to the service of Donald Trump, with a pompous promise to “negotiate an end” to Robert Mueller’s special counsel investigation, perhaps the media will provide a more complex and less hagiographic portrait of Rudy than the reams of fanboy pap that chronicled his rise.

His mayoralty ended a long time ago, and there is much worth examining since then, from his dubious legal clients and mystifying security contracts to his effort to manipulate the FBI on behalf of Trump. But any journalist seeking the real Rudy should start in the same place where so many smart reporters first hunted for the real Donald — in the collected works of one of America’s greatest investigative reporters, the late Wayne Barrett (my close friend, stern mentor, and longtime colleague).

His books Rudy! An Investigative Biography of Rudy Giuliani (Basic Books, 2000), and Grand Illusion: The Untold Story of Rudy Giuliani and 9/11(HarperCollins, 2006, and co-authored by the estimable Dan Collins) shined a laser light on their subject’s flaws, foibles, and outright falsehoods.

Rudy!  broke news with its exposure of Giuliani’s father Harold as a small-time hoodlum and its account of Rudy’s sexual buccaneering, but should be read for its unsparing critique of his mayoral record and authoritarian style. Grand Illusion revealed for the first time the massive, tragic failures of planning and execution, driven by ego and cronyism, that lay behind his undeniably admirable performance on the day of the disaster — and undoubtedly cost lives.

From the devastating Grand Illusionexcerpt that appeared in the August 22, 2006 edition of The Village Voice, where Wayne reported for nearly four decades:

Rudy Giuliani’s performance on 9-11 is legendary, but for most people, the story boils down to one image: the mayor walking north from the disaster, covered with dust. Afterward, in his greatest achievement, he was able to give voice to all the things the rest of us needed and wanted to hear. He articulated our grief, shored up our confidence, and insisted on a level- headed response that gave no berth to intolerance. We resist knowing anything more—about the eight-year history of error and indifference that preceded that moment, or the toxic disengagement that followed it…

We rely on our leaders to behave well in such a moment, to set an example of calm and compassion. But we do not expect them to manage the intricacies of the rescue operation. For that, we hope there are men and women throughout the government who have been preparing and training just so that if a crisis comes, they can operate on instinct, yet automatically make the proper decisions. If the mayor of New York had made sure that the city’s emergency headquarters was securely located and had put in place communications and command systems that worked, he would have been of greater service on 9-11—even if he had spent the whole day cowering under his desk.

Giuliani has never acknowledged a single failing in his own performance. Yet he did nothing before September 11 to alleviate the effects of a terror attack. He embodied his city’s lack of preparation on West Street that morning. And he did not do anything later that matched the moments of grace and resolve he gave us the day we needed him most. What we have left is this: At a moment when the public needed a hero, Rudy Giuliani stepped forward. When he assured New York that things would come out all right, he was blessedly believable. It was a fine thing. But it was not nearly as much as we, at the time, imagined.

IMAGE: Republican presidential nominee Donald Trump walks with former New York City Mayor Rudolph Giuliani (L) and his son Eric Trumo (R) through the new Trump International Hotel in Washington, D.C., U.S., September 16, 2016. REUTERS/Mike Segar