WASHINGTON — Democratic presidential candidate Kamala Harris’ campaign is dismissing accusations that she and a co-author plagiarized parts of a 2009 book on the U.S. criminal justice system as a desperate attempt by “rightwing operatives” to distract voters.

Plagiarism experts and academics who reviewed the claims said several were benign or could not be proven and others were more due to careless writing than malicious intent.

The allegations surrounding the book, “Smart on Crime: A Career Prosecutor’s Plan to Make Us Safer,” surfaced Monday when conservative activist Christopher Rufo posted an article on his Substack platform that listed a handful of passages he said were copied from other sources without any or adequate attribution.

“Taken in total, there is certainly a breach of standards here,” Rufo wrote. “Harris and her co-author duplicated long passages nearly verbatim without proper citation and without quotation marks, which is the textbook definition of plagiarism.”

James Singer, a spokesman for the Harris campaign, said in a statement that the plagiarism allegations represent a partisan attack on a book Harris co-authored more than a decade ago.

“Rightwing operatives are getting desperate as they see the bipartisan coalition of support Vice President Harris is building to win this election, as (former president Donald) Trump retreats to a conservative echo chamber refusing to face questions about his lies,” Singer wrote. “This is a book that’s been out for 15 years and the vice president clearly cited sources and statistics in footnotes and endnotes throughout.”

Rufo’s article cited a new study of Harris’ 248-page book by Stefan Weber, an Austrian academic known in Europe as a “plagiarism hunter.” Among the findings, the book plagiarized a section from a Wikipedia article and made up a childhood anecdote that originated with Martin Luther King Jr., according to Weber.

Trump’s running mate, Ohio Republican Sen. JD Vance, seized on the allegations to needle Harris.

“Hi, I’m JD Vance. I wrote my own book, unlike Kamala Harris, who copied hers from Wikipedia,” he wrote on X. Vance’s 2016 memoir, “ Hillbilly Elegy “ recounts his blue-collar upbringing in Kentucky and Ohio.

The allegation involving King centers on a story Harris said her mother told her about a time when she was fussing as a toddler. Her mother, according to the book, asked her what was wrong and what she wanted. “I wailed back, ‘Fweedom,’ ” Harris wrote. Weber said Harris appropriated the anecdote, without attribution, from an interview King gave in 1965.

But other plagiarism experts questioned the severity of the claims. Jonathan Bailey, a consultant and publisher of the website Plagiarism Today, said in a Tuesday post that the King story allegation first arose in early 2021 and couldn’t be proven based on available evidence. But several other plagiarism accusations are more troublesome, he said, including Weber’s allegation that Harris’ book copied and pasted, without citation, a section of a Wikipedia article. But the patterns in the book point to “sloppy writing habits, not a malicious intent to defraud,” he said.

“Though some of the passages, such as the Wikipedia one, are sloppy to the point of negligence, when you look at the portion of the book involved, the nature of the issues and the citations provided, negligence remains more likely than malice in my eyes,” Bailey wrote.

Miguel Roig, a psychology professor at St. John’s University in New York who studies plagiarism in the sciences, said the lapses described by Weber meet the definition of plagiarism. But, he said, context is important. The problematic passages amount to a small total of the overall book and “hardly seems like an attempt to defraud,” he said.

“Any time minor issues like these occur, the offending authors should simply acknowledge the obvious errors, apologize, and make corrections,” Roig said.

Harris wrote “Smart on Crime” when she was the district attorney for San Francisco. The book spelled out her ideas for improving public safety and making the criminal justice system more effective. In 2010, a year after the book was published, she was elected attorney general of California.