Armie Hammer and Felicity Jones in On the Basis of Sex (Jonathan Wenk/Focus Features)

On the Basis Of Sex is the feel-good movie of the year on the triumph over gender discrimination, and it is as inspiring as the recent documentary RBG, which is also about Justice Ruth Bader Ginsburg’s legal victories for women’s rights. What was missing from that film, though, was the human interest element of her crucial partnership with her tax lawyer/husband, Martin, especially on the only case they argued together.

At age 85, Justice Ginsburg has reportedly seen this movie at least three times before its Christmas Day opening and loved it each time. That’s after she had gone over the first three drafts of the script by her nephew Daniel Stiepleman, while her daughter, Jane, a Columbia Law School professor, went over countless drafts before director Mimi Leder started filming. So what if Felicity Jones and Armie Hammer do not look or sound at all like Brooklyn Jews Ruth and Marty Ginsburg. What Ginsburg presumably approves of is not only that the legalese is correct, as she insisted, but that the film well captures the feeling of the period from 1955 to 1971 and her life as a mother, wife, law student, professor, and litigator, as well as the changing times around her.

Justice Ginsburg has been quick to note the opening dramatic license. As a male chorus booms the traditional “Ten Thousand Men of Harvard” song, the camera pans the dark shoes of the Harvard Law School class gathering for orientation, and a pair of blue pumps glaringly sticks out—hers. She has demurred, “I never wore heels.” But the image very much gets across how she felt to be one of nine women in the class of 500, only five years after they were admitted at all.

In contrast, the first time we see Marty, he is fondly dangling their infant daughter Jane back in their apartment. Ruth tries to pick a conservative dress for a group dinner with misogynistic Dean Erwin Griswold (Sam Waterston), asking Marty, “Which one makes me look more like a Harvard man?” (She ends up making only a nervous impression.) While Marty is a year ahead at the school, he works most of the second shift at home, managing cooking and child care, as he did throughout their 50–plus year partnership. At a party, Marty is the one who charms all with humor, while she struggles for attention in the stern class of Professor Brown (Stephen Root), even though she has the correct answers.

That is, until her husband is struck with cancer in his last year at law school. She begins covering his classes, too, reading lecture notes to him so that he’s able to study during a difficult recovery. (There’s just a glimpse of friends helping with babysitting and school.) After he graduates, they move to New York when he lands a job there. Those fictitious blue heels pound the pavement again after Columbia Law School, as she tries to get a job in New York with law firms large or small. Marty is full of encouragement. But she’s the one finally willing to compromise and take an open teaching position at Rutgers Law School, saying cynically: “They haven’t found another black man to replace him, so someone decided a woman would be the next best thing.”

The times are a-changing around the couple, represented by their now-teenage rebel daughter (Cailee Spaeny). At Rutgers, Ruth starts a “Women and the Law” seminar, where her students, with long hair and large Afros, dress casually in jeans. Meanwhile, Marty provides her with the inspiration to do more, through the key case missing from RBG because it didn’t go before the Supreme Court. Here, Hammer makes a federal tax case sound like an irresistible seduction. He slyly leaves the tax decision for her to read, and she slowly rises to his delighted bait: “This is sex-based discrimination—against a man!” Since then, she has called this “the grandparent brief” for her career pursuing equal rights.

The process of pulling together the case has the usual elements of the underdog law suit movie, starting with Ruth convincing the client, Charles Moritz (Chris Mulkey), to let them represent him pro bono. Demonstrating how she recognized the impact of unfair law on individuals, she witnesses that he is genuinely responsible for his elderly mother and is justified in wanting a $296 tax deduction for the expense of her daytime caregiver.

In a made-for-the-movies but real coincidence, her Harvard naysayers Dean Griswold and Prof. Brown are now the Department of Justice senior attorneys opposing her suit. They are so sure the claim of gender discrimination is absurd that for their brief, they get a huge, room-size computer at the Pentagon to generate the first list of all the federal legislation that specifies one gender as a justification for the law. That list becomes the basis for the ACLU’s Women’s Rights Project, as Ruth’s students, joined by Jane, pour over the inequities.

To show her teenage daughter that change can come in the courts as well as in street demonstrations, she takes Jane to meet pioneering lawyer (and ACLU Board member) Dorothy Kenyon (Kathy Bates), who convinces reluctant ACLU Director Mel Wulf (Justin Theroux) to provide organizational cover for the suit. Tribute is also paid to African American lawyer Pauli Murray (Sharon Washington), who worked with Thurgood Marshall on developing the step-by-step legal strategy that led to Brown v. Board of Education. Ginsburg carefully followed her advice while feminist leaders were pushing for the more sweeping Equal Rights Amendment.

All this—the romance and the supportive spouse, the discrimination and the law—thrillingly come together in Marty’s and Ruth’s climactic oral arguments. (There is another moment that the justice says is a touch inaccurate for dramatic effect, that she became nervous and hesitated at first.) So when the time line fast forwards to the real-life subject climbing the steps of the Supreme Court building, it’s the crowning touch to this upbeat hagiography.