RBG documentarians Betsy West and Julie Cohen had both interviewed Justice Ruth Bader Ginsberg in the past, but it was when Ginsberg’s name was gaining steam in popular culture that the idea of doing a documentary was born.

“We said ‘hey, someone should do a documentary on Justice Ginsberg and it should be us,'” said West, who stopped by Deadline’s Sundance Studio along with Cohen.

The two met apprehension when they initially approached Ginsberg about the project. “Her response was ‘not yet,’ ” West continued.  “We took that as actually an encouraging sign that maybe she would be interested.”

In this instance, patience and persistency were key. “We kept at it and were persistent without being annoying, we hoped. Eventually she agreed to let us talk to her family and some of her former colleagues and clients and to film her at some of her public speaking engagements. And then we wormed our way even closer and were able to capture some intimate moments.”

Justice Ginsburg is a stark figure in the gender equality movement who, intent on systematically releasing women from second-class status, argued six pivotal gender-bias cases in the 1970s before an all-male Supreme Court blind to sexism. Now 84, Ginsburg refuses to relinquish her passionate duty, steadily fighting for equal rights for all citizens under the law.

RBG tells the electric story of Ginsburg’s consuming love affairs with both the Constitution and her beloved husband Marty—and of a life’s work that led her to become an icon of justice in the highest court in the land.

“She faced extraordinary discrimination and yet her strategy ultimately, a decade later, was to do something about this kind of discrimination that was just accepted,” said West.

Check out the interview above to hear about Justice Ginsberg’s high-intensity workout routine.

The Deadline Studio is presented by Hyundai. Special thanks to Calii Love.