Nancy Bush Ellis, the sister of one president and aunt of another, who for a time devoted herself to Democratic causes despite her family dynasty’s Republican lineage, died on Sunday at an assisted living facility in Concord, Mass. She was 94.
Her son Alexander Ellis 3d said the cause was complications related to Covid-19. She was hospitalized on Dec. 30 with a fever and tested positive for the coronavirus, he said. Her symptoms abated within days, he added, but her general health was failing.
Smart, athletic and outgoing, Ms. Ellis exuded the patrician charm of a bygone era, Jon Meacham, the historian and biographer of President George Bush, said in a phone interview. She was active, he added, at a time when public service was perceived as noble and politicians from the other party were not regarded as enemies.
“She was a Katharine Hepburn-like figure,” he said.
Unlike most of her family, Ms. Ellis was a liberal Democrat for decades, promoting environmental and antipoverty causes, raising money for the N.A.A.C.P. and serving as head of the New England section of the NAACP Legal Defense and Educational Fund.
Nonetheless, after one of her brothers, George Bush, announced he was entering the Republican primary for president in 1979, “there was no more fiercely loyal person on the planet,” Mr. Ellis said in an email.
“She was a wonderfully energetic campaigner and cheerleader for her brother,” he said.
She campaigned too for her nephew George W. Bush, who was governor of Texas before he became president in 2000. When Mr. Bush ran for re-election in 2004, Ms. Ellis campaigned for him not only in the United States but also in London, Paris and Frankfurt, Germany, on behalf of Republicans Abroad, an organization that encourages Americans overseas to register and vote.
“She was a Democrat for whom family came first,” Mr. Meacham said.
As an active environmentalist, Ms. Ellis was a board member and honorary director of the Massachusetts Audubon Society. She raised money to establish the Rio Bravo Conservation and Management Area in Belize. She also served on the board of Pact, which fights poverty worldwide.
She was quoted as saying, in reference to her brother, that for many years, “I was out in what George calls ‘deep left.’”
Nancy Walker Bush was born on Feb. 4, 1926, in Milton, Mass., a Boston suburb. Her father, Prescott Sheldon Bush, worked on Wall Street before he was elected to the United States Senate from Connecticut in 1952. Her mother, Dorothy Walker Bush, energetic and forceful, raised Nancy and her four brothers to be modest and socially responsible but also highly competitive.
“Her philosophy was, Give your all, try your hardest, do your best,” Ms. Ellis said of her mother in an interview with The Chicago Tribune in 1991 while her brother George was campaigning for re-election as president.
Like her mother, Ms. Ellis was a champion tennis player and an all-around athlete, her skills honed by competing against her brothers.
She attended the private school Rosemary Hall in Greenwich (now Choate Rosemary Hall in Wallingford, Conn.) and Miss Porter’s School in Farmington. Conn., and majored in English at Vassar, from which she graduated in 1946.
That was the year she married Alexander Ellis Jr., who would run the Boston insurance brokerage firm of Fairfield and Ellis. Ms. Ellis lived with her husband and four children in Concord. As the daughter of a well-connected senator during the Eisenhower and Kennedy administrations, she frequently visited her parents in Washington, enjoying its social scene.
She supported the Democrat Adlai E. Stevenson in his presidential campaigns and was enamored of President John F. Kennedy, another Democrat. One evening in 1963, at a state dinner for John Kenneth Galbraith, who was returning as ambassador to India, she was seated to the president’s right, traditionally a place of honor.
The arrangement caused a stir, with some remarking later that the woman next to the president was “a nobody.”
Surprised herself, Ms. Ellis asked the president during dinner why she had been accorded such an honor.
“Nan,” he told her, “you are the only woman here who is registered to vote in Massachusetts.”
When her nephew George W. Bush was a student at Harvard Business School in the early 1970s, Ms. Ellis had weekly lunches with him.
“My favorite aunt,” he called her.
“George,” she would reply, “I am your only aunt.”
After her husband died in 1989, Ms. Ellis moved to Beacon Hill in Boston and led an active social and cultural life. She supported the city’s arts, music and theater as well as numerous charitable and nonprofit organizations, including the United South End Settlements, which provide services for the poor; the New England Medical Center; and the New England Conservatory of Music.
Extremely well-read and a lifelong learner, she also participated in seminars at Radcliffe.
“She could just as easily quote Shakespeare sonnets as whistle a cross-court volley by your ear,” Alexander Ellis said of her tennis prowess. “She offered us kids $100 for the first one to beat her. No one did.”
Ms. Ellis spent half the year, from May to October, at her summer home in Kennebunkport, Maine, not far from her brother’s family compound at Walker’s Point.
In addition to her son Alexander, she is survived by two other sons, John Prescott Ellis and Josiah Wear Ellis, who is president and chief executive of the Denver Broncos; a daughter, Nancy Walker Ellis Black; nine grandchildren; 11 great-grandchildren; and a brother, Jonathan James Bush.
“She’s a part of this great American ethos that’s almost entirely gone,” Mr. Meacham said of Ms. Ellis. “She was the best kind of aristocrat. There was a sense of service without a shred of snobbery.”