Although I will never know the abuse now raining down on a Gov. Scott Walker or a Rep. Darrell Issa, I am beginning to get a firsthand glimpse of how the left's slander machine works.
Here is why. In September 2008, I first put into play the thesis that former terrorist Bill Ayers was the primary craftsman behind Barack Obama's acclaimed 1995 memoir "Dreams From My Father."
New Yorker editor David Remnick, like many on the left, sensed "the diabolical potency" of my thesis. "This was a charge," wrote Remnick in "The Bridge," his 2010 Obama biography, "that if ever proved true, or believed to be true among enough voters, could have been the end of the  candidacy."
In my just released book, "Deconstructing Obama," I prove this thesis beyond a reasonable doubt and show how the story that Ayers and Obama crafted, particularly about Obama's early years, is profoundly untrue.
The book was published by Simon & Schuster and vetted by its lawyers. The thesis was confirmed in some detail by the otherwise Obama-friendly celebrity biographer Christopher Andersen in his 2009 book, "Barack and Michelle: Portrait of an American Marriage." It deserves to be addressed dispassionately.
That, to say the least, has not been the case so far. Remnick had launched the slander campaign before there was a book. Given that Rush Limbaugh had talked about my thesis on the air, and Remnick (unfairly) considers Limbaugh a racist, he lumped us together and concluded that our collective libel had "a particularly ugly pedigree."
Although I had written a previous book on literary and intellectual fraud, "Hoodwinked," I had never heard of the "pedigree" in question, namely the denial of authorship to black writers.
On the off chance Remnick had spotted a latent bias in my attribution research, I went back and checked "Hoodwinked." I calculated the ethnic mix of my roughly 20 frauds and found that three were black – almost precisely the black percentage in the population.
Still, the racism charge was out there. The day of the book's release, David Martin, writing for Kansas City's leftist alternative paper, The Pitch, seized the low ground.
Wrote Martin, "Cashill believes that Obama didn't produce a book that people want to read because Obama can't produce a book that people want to read."
Although he had not read my book, Martin continued, "Sounds kinda racist, no? Editor and Pulitzer Prize-winning author David Remnick thought so."
Martin had a goal in mind. Two days later, I was to speak at the Kansas City Public Library, a presentation we had set up months earlier for the benefit of C-SPAN's admirable Book-TV, a program on which I have appeared five previous times.
Martin's publication, the Pitch, alleges to be an advocate for free speech. That notwithstanding, Martin asked, "Does such a book deserve the library's stage?"
This article provoked more protest calls than the library had ever received for a speaker. Had the library director not been a good friend, the presentation likely would have been canceled.
A week after the book's release, Media Matters for America weighed in. A left-wing "watchdog group" with ample funding – George Soros invested a cool million just last year – the high-minded Media Matters purports to root out ""conservative misinformation."
In reality, however, Media Matters mostly just smears people who disagree with its shifting progressive agenda. I felt both slimed and honored to get its attention.
To be sure, reviewer Simon Maloy repeated Remnick's "ugly pedigree" charge with all its implications, but at least he appears to have read the book. It is for readers like him that I cited Andersen's confirmation on the book's first page.
This must have taken Maloy back at least a little bit. He responded by ignoring Andersen completely, just as Remnick did in "The Bridge."
Although Maloy restricted himself largely to invective – e.g. "intellectually and morally offensive screed" – he did occasionally get specific. In one instance, he mockingly observed that my "candidates for Obama's 'real' father include Malcolm X and Jimi Hendrix."
This was nonsense, and he knew it. I wrote about Malcolm X only to debunk theories that he was the father. "Malcolm may have been the least likely candidate of any race to sire Obama," I wrote and explained why.
I introduced Hendrix "for those who insist on a celebrity father" in what I called a "Paul-is-dead" spirit. I concluded, "I can envision the mirthless Huffington headline now, 'Whack job from Web's farthest lunatic orbit says Hendrix Obama's father!'"
I wrote that last sentence to discourage the mirthless left from deliberately taking my Hendrix comment out of context. Maloy may have though it only applied to the mirthless left at the Huffington Post.
Predictably, Maloy's dissembling encouraged the review's respondents to howls of laughter and heaps of profanity. Wrote one typical respondent on the Hendrix/Malcolm X paternity claim, "Why would someone even suggest that? Unless of course they are seriously f---ing stupid."
Say what you will about the New York Times, but its editors would have fired Maloy over this conscious deception. Scarier still, Maloy is not some cub reporter like Jayson Blair, but Media Matter's "deputy research director."
The same day of the Media Matters review, the publisher of my previous book "Popes & Bankers" forwarded an e-mail he had received from a David Sessions of the Daily Beast.
"I'm interested in talking to the editor who worked with [Cashill]," Sessions wrote. He expressed particular interest in the largely apolitical "Popes & Bankers."
Sensing a hidden agenda, my publisher at Thomas Nelson instead passed the e-mail on to me. Although I knew nothing of Sessions, his most recent article on Congress, "House of Theocons," gave me a good sense of his regard for the truth.
Given the leftward tilt of the Daily Beast, I had little doubt about Sessions' larger intent, but was less certain as to why he would want to talk to my editor without ever contacting me.
Clearly, Sessions was circling back to "Deconstructing Obama." Was he hoping to learn that I, like Barack Obama, could not possibly have written my own book, especially one with an epic subtitle like "A Cultural History of Credit & Debt, From Aristotle to AIG"?
I e-mailed Sessions back, "David, I am sure I can answer your questions better than my editor can." To his credit, Sessions e-mailed me back saying that it "would be great" if we could talk.
I would love to talk. Mine is a serious critique, both from the perspective of literature and of history. I'm happy to discuss it with anyone who is willing to read the book and check his urge to race-bait at the door.
See what's causing leftist critics to froth -- order your copy of Cashill's "Deconstructing Obama."