Portman also explained that one of the aspects of playing the former first lady that she enjoyed the most was getting to explore who she was as a real human being, instead of the stoic public figure most people think.
"I was able to imagine separate aspects from her and it was incredible to get to think about someone deeply who I had only thought about as an icon before," Portman recounted. "She was really incredible."
"The thing that was so amazing was, at the moment of such private grief, she was able to think about the public and the image of what the family meant and the legacy of what the family meant to this country," she added. "It was a terrifying moment and she, in her resilience in the face of that, really took our country through the darkness."
Recently, ET sat down with Portman, who got candid about the pressure of playing Kennedy, and about how her children are her "good luck charms in life." Check out the video below to hear more.