A member of the Democratic Party , she served as mayor of San Francisco from to In , during a third stint as the board's president, the assassinations of Mayor George Moscone and City Supervisor Harvey Milk drew national attention. Feinstein succeeded Moscone as mayor and became the first woman to serve in that position.
During her tenure , she led the renovation of the city's cable car system and oversaw the Democratic National Convention. After losing a race for governor in , Feinstein was elected to the U. Senate in a special election. Feinstein was reelected five times. In the election , she received 7. Senate candidate in history. She chaired the Senate Intelligence Committee from to [ 12 ] and was the ranking member of the Senate Judiciary Committee from to Feinstein's last years in office were marred by poor health and concerns about her mental acuity to serve.
She was also the longest-serving U. Her paternal grandparents were Jewish immigrants from Poland. Her maternal grandparents, the Rosenburgs, were from Saint Petersburg , Russia. Feinstein's sister, Yvonne Banks, said their mother had unpredictable moods. Later, Feinstein's mother received a brain scan that found that the part of her brain responsible for judgment had atrophied , "possibly because of complications from a severe illness as a child".
From to , Feinstein was a fellow at the Coro Foundation in San Francisco, an organization that provides young people with political experience.
She served on the board until Feinstein was elected to the San Francisco Board of Supervisors in During her tenure on the Board of Supervisors, she unsuccessfully ran for mayor of San Francisco twice, in against Mayor Joseph Alioto , and in , when she lost the contest for a runoff slot against George Moscone to Supervisor John Barbagelata.
