The text message from Christine Blasey Ford this summer worried her college best friend, Catherine Piwowarski.

Over their years of friendship — as roommates, bridesmaids and parents on opposite coasts — Dr. Blasey wanted to know, had she ever confided that she had been sexually assaulted in high school?

No, Piwowarski said she texted back, she would have remembered that, and was everything OK? Blasey didn’t want to speak in detail quite yet, her friend recalled her responding. “I don’t know why she was asking that or what it ultimately meant or didn’t mean,” Piwowarski said in an interview, but she remembers thinking that the question betrayed deep turmoil.

That was about a month before Blasey, a research psychologist, came forward with her allegation that Judge Brett M. Kavanaugh, President Donald Trump’s Supreme Court nominee, sexually assaulted her more than three decades ago when they were high school students in the Washington suburbs.

Just days ago, both Blasey and Kavanaugh — who has denied sexually assaulting her, or anyone — had been expected to testify on Monday before the Senate Judiciary Committee about the allegation, setting up a contest of credibility reminiscent of 1991, when Anita Hill leveled accusations of sexual harassment against Clarence Thomas, then a Supreme Court nominee. But it is increasingly uncertain whether that will happen. Blasey’s lawyers on Tuesday called for an FBI investigation of her allegation before she testifies, but the Senate Republican leadership has rejected the idea and said that a vote on the Kavanaugh nomination will go forward if she does not appear.

Blasey’s allegation has divided not just the Senate and the country, but also the overlapping social circles of the judge and the researcher, as former classmates, colleagues, friends and others have written warring letters of support in recent days. Blasey’s lawyers, Debra Katz and Lisa Banks, say that since she went public with her story last weekend, she has been subjected to death threats, had her email hacked and had to leave her home. Speculation has arisen in the capital that Blasey, who had already been reluctant to come forward, may ultimately decline to testify, at least publicly.

Supporters of Blasey, 51, describe her as a precise, logical scientific thinker; a community leader; a woman of integrity; and a devoted mother of two boys.

“Her life’s work is about telling the truth with science,” said Kate Beebe DeVarney, a behavioral neuroscientist who has worked with Blasey in Silicon Valley. “Christine doesn’t get stuff wrong. She’s obsessive about making sure it’s right,” she added. “If Christine says something happened, I absolutely believe her.”

Backers of Kavanaugh, 53, describe him as a precise, methodical legal thinker; a strong mentor; a pillar of the community where he and Blasey grew up; and a devoted father of two girls. Trump this week praised the judge as an “outstanding intellect,” who “never had even a little blemish on his record.”

Kavanaugh, a Republican, is a staunch Catholic conservative who lives in the nation’s capital. Blasey, colleagues say, is a Democrat from California who wore a pink “brain hat” when she joined fellow academics in protesting the Trump administration’s proposed cuts to scientific research funding. Their histories coalesced, in Blasey’s telling, in the early 1980s, in the insular, moneyed world of Washington private college preparatory schools.

Intersecting Social Circles

She began attending Holton-Arms School, a private girls’ prep school in Bethesda, Maryland, in seventh grade, joining a tight-knit group of about 65 girls. High school friends and classmates described “Chrissy,” as Blasey was known then, as a popular girl equally comfortable in math class and at social gatherings.

Samantha Semerad Guerry said Blasey fit right in. Athletic and outdoorsy, she joined the soccer, softball and cheerleading teams.“She was universally well-liked — always cheerful, affable, funny, and super smart,” Guerry said.

“She was self-possessed,” recalls Cheryl Aviva Amitay, who graduated in 1985, the year after Blasey.

As a student at Holton-Arms, Blasey was part of an elite, suburban Washington community, where the families of members of Congress, white-shoe lawyers and lobbyists golfed, played tennis and swam together at a hierarchy of country clubs; Blasey’s father, a business executive, formerly served as president of the Burning Tree Country Club. Students at private schools socialized with one another and participated in cross-school events.

Children from Catholic schools, like Georgetown Preparatory School, which Kavanaugh and Justice Neil Gorsuch attended, and Stone Ridge School of the Sacred Heart, a girls’ school nearby, tended to hang around together, having often come from the same parishes and grade schools, though not exclusively. Guerry said that she knew Georgetown Prep boys through participating in school performances, and that Brett Kavanaugh was an acquaintance.

Drinking was commonplace among the private school teenagers, and the laws governing alcohol and minors were more lax than now. “Back then, pretty much there were parties every Friday and Saturday night, somewhere,” said Samu Qureshi, a friend of Blasey’s who attended Landon, the brother school to Holton Arms, two years ahead of her. “Generally, parents are out and the kids are getting a keg.”

Holton-Arms’ yearbook includes pages of photographs of girls with drinks. Boys would be invited from the surrounding schools — Landon, Georgetown Prep, and St. Albans — for dances. Things could get rowdy, especially at unsupervised parties before and after school functions, students from that era recalled.

A yearbook entry for Kavanaugh, a varsity football and basketball player at Georgetown Prep, described him as “Keg City Club (Treasurer) — 100 Kegs or Bust.” Mark Judge, a classmate and close friend, describes his own blackout drinking during those years in “Wasted: Tales of a Gen X Drunk,” his 1997 memoir about his experiences as a teenage alcoholic. The book mentions a person named “Bart O’Kavanaugh” who had “puked in someone’s car” and “passed out on his way back from a party.” Judge did not respond to queries this week about whether that name refers to Kavanaugh.

This was the environment in which Blasey, when she was about 15 years old, encountered Kavanaugh at a gathering at another teen’s house in Montgomery County, Maryland, she said. She knew him before the alleged incident, she has said, countering a theory of mistaken identity advanced by Kavanaugh and his supporters in the Senate.

She had met him a couple of times, though they didn’t run in the same circles and weren’t friends, a person close to Blasey said, speaking on the condition of anonymity to discuss a personal matter.

According to a letter sent to Sen. Dianne Feinstein in July, Blasey claimed that Kavanaugh pushed her into a bedroom as she headed upstairs to a bathroom. He and someone she described as a “very drunken” friend — identified in later news reports as Judge — locked the door and played loud music, she wrote. Kavanaugh then pushed her on a bed, began grinding his body against hers and tried to undress her, she said. To stifle her screams, she asserted, he covered her mouth with his hand.

Judge, Blasey alleged, told his friend to alternately “go for it” and “stop.”

When Judge jumped on the bed, causing the three teenagers to tumble onto the floor, Blasey said she ran from the room, locked herself in the bathroom and escaped after hearing the two inebriated boys stumbling down the stairs.

Blasey said she did not share a detailed account of the incident with anyone until 2012, when she and her husband, Russell Ford, an engineer, met with a couples therapist, according to a Washington Post interview. In her letter to Feinstein, she described being traumatized from the high school episode, saying “I have received medical treatment regarding the assault." She declined to be interviewed for this article.

Judge, now an author, filmmaker and writer for conservative publications, wrote in a letter to the Senate Judiciary Committee that he had no memory of the incident, adding that he “never saw Brett act in the manner Dr. Ford described.”

Blasey’s allegation has ignited heated controversy in Washington’s private school circles, reflecting the same social divisions — by gender, alma mater, class and religion — that had riven alumni as teenagers more than three decades ago. Some Georgetown Prep classmates have cast aspersions on Blasey on social media, while her allies charge hypocrisy in their overlooking a pervasive culture of misogyny that existed then.

Twenty-three members of Blasey’s class at Holton-Arms signed a joint letter sent to Congress this week, calling for “due consideration” of her claims. Another letter is signed by more than 1,000 alumnae, dating back to the class of 1948. When Guerry circulated the letter from the class of 1984, she found that Blasey’s story resonated deeply. “I was very much surprised by how many of my classmates wrote back to say to say they had traumatic experiences in high school,” she said. “When they heard Christine’s story, it struck a chord for them.”

Among them was Cheryl Amitay, a chief regulator at the Department of Veterans Affairs living in Washington. Amitay said she was leaving a house party during her sophomore year when two male teenagers who had been drinking pushed her up against a car and groped her. One reached under her skirt, she said, and tore off her underwear.

“I will never forget that,” she said. “When my mom picked me up she knew something was wrong, but I didn’t say anything.”

“You never say a thing,” she went on. “You feel like a jerk.”

After the alleged attack on Blasey, a male friend said, she “fell off the face of the earth socially,” failing to appear at parties and events she’d previously attended. “All I remember is after my junior year thinking, ‘Where’s Chrissy Blasey?'” he recalled.

“She was the sort of person a lot of people paid attention to — she was a leader, she was great. I was like, where did she go?” A Researcher in Demand

Blasey said the experience “derailed” her for four or five years, and that she struggled academically and socially, according to The Washington Post. She went on to attend the University of North Carolina at Chapel Hill, where she studied psychology. The school’s alumni directory and yearbook list her as having belonged to the Kappa Delta sorority, which had a reputation as the “cheerleading sorority” in the 1980s, though she was not a cheerleader at the school. She seems to have kept a low profile.

“I don’t remember her very well,” said Leigh Goodwyn, who was a member of the sorority at the time. “There are not many people in the house I can say that about.” Two other sorority sisters also had trouble remembering her.

But she became close with Piwowarski. They would watch new bands perform in bars on the town’s Franklin Street, hanging out with friends, and roomed together in an off-campus apartment their senior year.

After graduating from UNC in 1988, Blasey moved to California, where she earned graduate degrees from Pepperdine, Stanford and the University of Southern California. When she married Ford in 2002 in Half Moon Bay, California, against a backdrop of redwood trees, Piwowarski was a bridesmaid.

Blasey developed a passion for surfing, which she shares with her husband and two sons. “She’s been chasing waves,” said Beth Stannard, a friend and former co-worker, who said Blasey’s decisions to teach at Pepperdine, in Malibu, California, and to complete an internship at the University of Hawaii were at least partly informed by the campuses’ seaside locations. She and her family live in Palo Alto — where she has volunteered for her sons’ schools and junior lifeguard training, has restored her midcentury modern home with an eye toward historical preservation, and has attended Stanford football and basketball games with her family. The family also has a house in Santa Cruz, famed for its beaches and breaks.

“She can be quite the academic — someone taken very seriously at a place like Stanford — and then go out and surf with the people of Santa Cruz,” Stannard said, recalling that Blasey had taken her and several colleagues surfing, followed by a lunch of fish and chips.

Fellow scientists described her as a collaborative researcher and statistician, in demand among graduate students and fellow researchers who sought her more refined writing skills for reports and papers. At the University of Southern California School of Education, she worked for several years in the laboratory, where she developed a test to assess how young children cope with trauma.

“She was very meticulous with data, looked carefully at developing children,” Dr. Gayla Margolin, who led the lab, said in an interview. “In doing good science, people have to take in information and reflect it and portray it in a very honest, straightforward way.”

Blasey was hired in 2012 by Palo Alto University, to teach as part of its doctoral psychology program, a consortium with Stanford that emphasizes clinical training. She is a co-author of a guide to statistical power analysis called “How Many Subjects?” used by researchers to determine how large a sample size is required to accurately test a hypothesis.

Dr. Barr Taylor, a professor emeritus of psychiatry at Stanford who for a decade chaired dissertation committees in which Blasey was involved, described her as somewhat reserved. “The statistics fit her personality more than the statistics shaped her personality,” Taylor said.

DeVarney, the Silicon Valley neuroscientist, calls Blasey “a friendly but kind of geeky scientist,” who is “obsessive about making sure it’s right.” The two worked together at three companies over 10 years.

DeVarney said Blasey called her in August to say that she had sent a letter to Feinstein about having been sexually assaulted in high school, “something that had haunted her for her entire adult life.” Blasey did not name the alleged attacker.

“She was clearly upset about it,” DeVarney recalled. “It was creating a lot of stress for her, and now it’s taken over her life.”

Preparing to Speak Out

After Blasey decided to come forward with her allegation and notify Feinstein, she, and later her lawyers, took steps to prepare for the fight of her life. She submitted to a polygraph, gathered notes from her therapist and searched her memory.

“I’ve been trying to forget this all my life, and now I’m supposed to remember every little detail,” Blasey told a friend, Jim Gensheimer, in July, according to an account in The San Jose Mercury News.

Later in the summer, she texted Piwowarski, her college friend. The query was worrisome, and Piwowarski told Blasey that she was there for her. It wasn’t until Sunday night that Piwowarski learned the details of her friend’s account from news reports.

A resident of New Bern, North Carolina, which was devastated by Hurricane Florence, Piwowarski said she read the story when the power came back on at her house. She felt sickened by it, she said.

“Seeing what people say, I really, really understand why somebody wouldn’t want to be a part of this discussion,” she said. “I think it is brave. But it is a lot to take on.”