Ten years ago, when Jimmy Carter was running for the Presidency, a young girl named Jennifer Cabranes wrote a letter to Amy Carter, asking her about her life. The two girls became pen pals, and in 1977 the Carters invited Jennifer, whose father is a federal judge, to spend a weekend with their daughter at Camp David. Remembers Cabranes, "Amy was a shy, sweet, politically indifferent girl."

What a difference a decade makes. Carter and Cabranes, who are both 19, met again this month in Massachusetts. Amy, a sophomore at Brown University in Providence, R.I., was in Northampton to stand trial with 14 others on charges of trespassing and disorderly conduct stemming from a Nov. 24 protest against CIA recruitment at the nearby University of Massachusetts. Jennifer, a U. Mass. sophomore and a Young Republican who writes for a conservative campus publication, says, "If people want to be interviewed by the CIA, they should be allowed to. Amy had no right coming up here." After an eight-day trial, a jury of not quite Amy's peers (a mostly elderly group of Hampton County residents) disagreed. With the defense citing a Massachusetts law that protects civil disobedience, the jurors acquitted Amy and her cohorts, apparently believing they were justified in occupying a campus administration building because they were trying to prevent larger crimes by the CIA.

That decision would have pleased Henry David Thoreau—not to mention Abbie Hoffman, the 50-year-old activist who was one of Amy's co-defendants. Like most Americans, Hoffman remembers Carter as the bookish First Daughter who seemed uncomfortable with fame. Now, he says, Amy has become "an important force in campus activism in this country. You can't name anyone, left, right or center, under 30, who is doing more than she is."

The pairing of Hoffman and Carter teams the ultimate self-promoting antiauthoritarian with a girl who grew up in the center of power. What's more, Abbie jokes, "I'm Northern, Jewish and outgoing." Amy is none of those things, but the two became friends during the November sit-in, their subsequent six hours in jail and the four months of planning for the trial. At one point they were spending so much time together that when Amy attended a lecture at U. Mass. by "Gonzo" journalist Hunter S. Thompson, the campus paper pointed out in a front page story that Amy was "not with Abbie Hoffman." In fact Abbie (whose oldest daughter, also named Amy, is 24) seems uncomfortable with even short separations from his New York home and Johanna Lawrenson, 46, his companion for 13 years. "Amy and I like each other," jokes Hoffman, "but we're not an item."

No, more like a mutual admiration society. In Hoffman, Carter has found a mentor. Their conversations are full of talk of civil disobedience, which they refer to as "CD." "Abbie told us not to give up hope," she says. "He convinced us that we could get good witnesses for the trial." Their strategy, which paid off, was to enlist critics of the CIA to testify that the agency is conducting an illegal war in Central America and committing other crimes. (Massachusetts law says that an offense committed to prevent a larger crime is not a crime.) Among the 11 witnesses they called was former Attorney General Ramsey Clark, who told the jury matter-of-factly, "The CIA seems uninhibited by law."

But Carter also gave effective testimony. During her 15 minutes on the stand, she said, "Every time a person sacrifices himself for a larger injustice, it aids in the cycle of change." At the end of her testimony, supporters in the visitors' gallery broke out in applause. Hoffman says, "I think Amy's account of why she did what she did is a historical document that people will be talking about in 30 years.

"Amy laughs when I say this," Hoffman continues, "but she has the best political instincts I've ever seen. And she handles the media better than I do. I've read all her interviews, and I've never seen a mistake." Surprisingly neither Hoffman nor Carter worried that his past (which includes a conviction for selling three pounds of cocaine) would prove detrimental to her future. Nor was she afraid to trust someone very much over 30. Says Amy, "The other defendants and I talked about it, and we figured anyone who was willing to take part in our demonstration was an all right person to have on our side."

Amy seems prepared to deal with all kinds of abuse. During the U. Mass. demonstration, her opponents shouted, "Amy, you dyke, why don't you shave your legs?" Amy answers, "When they're that misinformed, it's easy to blow them off." Harder to blow off was the group that chased her menacingly when she emerged from the courthouse one lunchtime. Amy, who has no Secret Service protection, abandoned a trip to the local Bagel Deli and returned to the courtroom in tears. She also allowed herself to become the focus of unrelenting media attention, despite her unhappy memories of the Washington press corps. The publicity, she figures, "is bad for me but good for the group." Says Abbie, "She has made an enormous number of sacrifices in her personal life for the cause."

Ironically Hoffman, who wore ties to the courthouse every day, now looks more yuppie than yippie, while Carter, who appeared in faded denim skirts with rainbow patches and loose men's sweaters, looks like a throwback to the '60s. She admits, "My mother wishes I'd dress neater." Still her actions are in no way a revolt against her parents. Amy, who spoke to Jimmy and Rosalynn during the trial, said, "They showed their support by only being concerned about whether I was missing too much schoolwork. They never said, 'Why are you doing this crazy thing?' " Activism is hardly novel in the Carter family (whose matriarch, Miz Lillian, was a Peace Corps volunteer at 68). Says Amy, "In my position, I could be a debutante. But we only got to this position by being a politically active family."

Another reason for the Carters' support may be Jimmy's not-so-secret dislike for the CIA, which failed him by not providing the intelligence that might have prevented the Iran hostage crisis. According to Amy, "My father would agree that Reagan has let the CIA go wild, and he'd agree that something has to be done." Still, cautions Abbie, "Amy is very much her own person. Jimmy Carter was in no way a patron of this trial."

Abbie and Amy both planned to be in Washington for an April 27 anti-CIA protest. Meanwhile Hoffman is working on his eighth book, Steal This Urine Test, a critique of what he considers to be Reagan's "drug hysteria." Amy is back at Brown trying to catch up on her schoolwork, which includes courses in feminist studies and Native American literature. She too says change is in the air. "People on campus are sympathetic, even the ones who don't agree with me. That wasn't true freshman year. The attitude has changed."

Even Cabranes is understanding, in a way. She says, "I disagree with the decision, but if I'd seen Amy after the verdict, I would have congratulated her. I didn't want her to go to jail." During the trial, Cabranes, one of a group of 20 pro-CIA demonstrators, marched in front of the courthouse with a banner emblazoned with snapshots from her weekend at Camp David. Last week, she says, she put the pictures "back in my scrapbook, for safekeeping." And the banner that carried them is in storage, in the office of the U. Mass. Republican Club. With the pictures removed, it carries just three important words: "Amy, what happened?" After the trial, it would seem that question has been answered.