The flap over a new book on Ronald Reagan centers on accusations of plagiarism but actually highlights the danger of devaluing what it means to be a historian, a Heritage Foundation scholar says.

Rick Perlstein’s book “The Invisible Bridge: The Fall of Nixon and the Rise of Reagan,” has come under fire not only for passages that resemble those of another Reagan biographer, Craig Shirley, but also for misstating facts and understating sources.

“Mr. Perlstein is calling into serious question the place of the historian at a time where we need to understand the past more than ever before,”  Lee Edwards, the distinguished fellow in conservative thought at The Heritage Foundation, told The Daily Signal.

Edwards, author of biographies of Reagan, Barry Goldwater, William F. Buckley and other conservative luminaries, is a respected chronicler of the American conservative movement.

While shifting citations of his sources online, Edwards said, Perlstein employs ideologically “loaded adjectives and cheap shots”  — Reagan is “a phony and a hustler,” “the candidate from Disneyland,” a “diarrhea mouth”  — to paint illegitimate pictures of Reagan, Goldwater and Richard Nixon as “dividers” of America.

And that, Edwards said, “is simply not true.”

Shirley, also a prominent Republican strategist, called foul shortly after the Aug. 8 release of “The Invisible Bridge.”

Shirley specified 45 instances in which he said Perlstein, a liberal author and journalist who was a senior fellow at the Campaign for America’s Future, appears to lift, without citation, material from Shirley’s 2004 book “Reagan’s Revolution.”

“There are no footnotes, endnotes, bibliography or other common form of citation in his book,” Shirley told Breitbart News in a detailed critique.

Instead, Shirley said, “buried on page 810, Mr. Perlstein directs readers to access his personal website where, after several clicks, they can uncover ‘A Note on Sources’ for ‘The Invisible Bridge.’ There, Mr. Perlstein credits some — but not all — of his uses of ‘Reagan’s Revolution.’ ”

A spokesman for Perlstein’s publisher, Simon and Schuster, called the allegations “ludicrous.”

Edwards, a leading historian of American conservatism, told The Daily Signal that he isn’t so much concerned with his own work being plagiarized — although his copy of “The Invisible Bridge” is filled with bright pink sticky notes — but rather, about the role of the historian in the modern day.

In a scathing review posted Aug. 13 by the venerable conservative journal Human Events, Edwards gives several examples of Perlstein’s failure to cite a source for a key assertion.

Edwards also notes that a previous Perlstein book “lifted portions of my Goldwater biography without citing my work.”

Soon after his review appeared, Edwards received an email from Perlstein thanking him for pointing out “deficiencies” in his footnotes.

“I’ll be able to correct them,” Perlstein wrote. “Very soon will have a wiki-style system that will record and time-stamp all additions and subtractions and changes, so both mistakes and missing sources, will be transparent in real time.”

He urged: “Keep ‘em coming if you notice others.”

If Perlstein doesn’t shape up, Edwards quipped  to The Daily Signal, he “might be consigned to the ash heap of historians like Edmund Morris.” The Heritage scholar added:

“At worst, it’s plagiarism. At best, it’s sloppy, careless, ideological writing.”

A footnote: Asked to comment on this report, Perlstein at first declined but later  e-mailed The Daily Signal about the three examples of  “loaded adjectives and cheap shots” about Reagan cited above by Edwards, writing:

All three of the sentiments Edwards claims come from me are in fact quotations
of what other people thought about Reagan. The first was a neutral observation:
some Americans do indeed think Reagan was a phony and a hustler. (I don’t ) The
second was quoted precisely in order to hold up to ridicule the tendency of many
liberals to foolishly underestimate him. The third came from his first wife, and
was adduced for the purpose of demonstrating what led to his divorce.