Supreme Court Justice Brett Kavanaugh's confirmation hearings created an atmosphere so tense that U.S. senators almost traded blows before the final vote, a new book claims.

Once the Judiciary Committee capped off days of contentious hearings by sending Kavanaugh's nomination for a final vote, things literally heated up in a small anteroom just outside of where the hearings took place.

According to authors Carrie Severino and Mollie Hemingway, the anteroom became "unbearably hot" on Sept. 28, 2018, as lawmakers crammed themselves into a tiny corridor where squabbles became so personal, a senator would periodically suggest staffers leave the room.

"In the epic, hours-long fight outside the meeting room, fistfights nearly broke out," the authors wrote in their book, "Justice on Trial: The Kavanaugh Confirmation and the Future of the Supreme Court."

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"One senator told another that he wanted to wring his neck," the book claims.

"A staffer who was bringing lunch to her hungry boss found herself in the middle of the scrum, with Ted Cruz inadvertently standing on her foot and Sheldon Whitehouse spraying her with saliva as he debated a colleague."

The book, released on Tuesday, offers a behind-the-scenes look -- packed with details like the ones above -- at what was perhaps the most contentious Supreme Court confirmation in decades.

Severino and Hemingway talked with more than 100 sources to paint a picture of, in part, just how divided the Senate became while determining who would shift the balance of power on the nation's highest court.

READ EXCERPT FROM 'JUSTICE ON TRIAL'

Hemingway, a senior editor for The Federalist and Fox News contributor, told Fox News during an interview that Kavanaugh's confirmation hearings were a marked departure from the typically collegial atmosphere on the Judiciary Committee.

"That is one of those committees that has had a reputation of getting along pretty well across different parties," she said.

Throughout the confirmation process, lawmakers chided one another in a series of disagreements that seemed to culminate in the tense standoff that took place inside that Senate anteroom.

"Many people told us it was the craziest thing they ever experienced in their time on the Hill," Hemingway told Fox News during an interview.

"It was just a boiling point and it all boiled over," Hemingway also said. Just before the meeting, the book claims, Sen. Kamala Harris, D-Calif., "was heard lamenting that the Republicans were beating the Democrats, liberally punctuating her complaint with f-bombs."

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Hemingway described the tension as resulting from multiple factors including divergence between what senators verbally committed to and what their staffers actually did. Severino noted during an interview with Fox that in some instances, senators bypassed potential areas of agreement because of staffers' influence.

The book primarily focused on difficulties stemming from Democrats' refusal to cooperate; staffers not partaking in a committee call, senators refusing to respond to a roll call, and another senator referring one of Kavanaugh's obscure accusers to a reporter rather than proper investigative channels.

The extreme elements of some staff members, Severino indicated, upset moderate Democrats as well. Because staff was so "unreasonable," Hemingway argued, they doomed their chances of participating in compromises that would have effectively secured their goal of delaying a vote.

The committee's ranking member, Sen. Dianne Feinstein, D-Calif., angered Republicans during the early stages with her decision to withhold knowledge of Christine Blasey-Ford's allegation long before the soft-spoken psychology professor testified in September. According to the book, that decision also appeared to come primarily from her staff rather than the senator herself.

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The hearings also held an air of "stagecraft" that Hemingway suspected was also a factor in the lead-up to that meeting. Blasey-Ford, for example, wore a blue suit that Sen. Mazie Hirono, D-Hawaii, reportedly praised as an allusion to Anita Hill's outfit during Justice Clarence Thomas' hearings.

While making that comment to Harris, she also complimented how Blasey-Ford's attorney requested a "Coke" for his client -- for her, an apparent reference to a crude allegation that Hill lodged at Thomas.

Hirono, the authors said, also included a query about indigenous people in the unprecedentedly long list of questions the committee gave Kavanaugh, a move they suspected the Hawaii senator made in an attempt to persuade another swing vote -- Republican Sen. Lisa Murkowski of Alaska -- after already pledging, like other Democrats, to oppose Kavanaugh's nomination.

Judiciary Republicans similarly hoped prosecutor Rachel Mitchell -- whom Severino and Hemingway defend amid criticism from both sides of the political spectrum -- would influence Senate Republicans like Flake and others who weren't on the committee.

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Flake, who was the critical swing vote in sparking that anteroom fight, eventually delayed the final vote by requesting another investigation. Former President George W. Bush tried convincing Flake to support his former appellate court nominee but was unable to reach him by phone.

In his stead, Senate Majority Whip John Cornyn, R-Texas, apparently tried to persuade Flake by leaning into a small phone booth inside of which both Flake and Sen. Chris Coons, D-Del., struggled to fit. "They made an absurd picture huddled around a cell phone, their limbs intertwined," Severino and Hemingway wrote.