Mazie Hirono (born November 3, 1947, near Fukushima city, Japan) is a Japanese-born American politician who was elected as a Democrat to the U.S. Senate in 2012 and began representing Hawaii the following year. She was the first Asian immigrant and the first Buddhist to serve in the Senate and the first woman to represent Hawaii in that legislative body. Hirono previously served in the U.S. House of Representatives (2007–13). In 2024 she comfortably won reelection over her Republican opponent Bob McDermott.
Hirono was born in a village near Fukushima city, Japan, to a Japanese American mother and a Japanese father whose marriage later dissolved. Mazie and her brother Roy moved with their mother to her native Honolulu in 1955. Mazie earned a bachelor’s degree in psychology from the University of Hawaii in 1970 and, after working for a few years, received a law degree from Georgetown University in 1978. She then returned to Honolulu and worked for the state government in antitrust litigation before being recruited to run for the Hawaii House of Representatives in 1980. She won the election and took office the following year. She served until 1994, when she ran for and won the post of lieutenant governor.
In 2002 Hirono was defeated for the governorship by Republican Linda Lingle. Four years later Hirono won a seat in the U.S. House of Representatives, and she served three terms. In 2012 she ran for the U.S. Senate to replace retiring Sen. Daniel Akaka. She defeated Lingle in the general election and assumed office in 2013. She easily won reelection in 2018, and earned a reputation as a determined critic of the policies of Pres. Donald Trump. A liberal Democrat, Hirono typically voted with her party’s leadership. She also sponsored numerous bills related to education and took a strong pro-choice position on abortion.
Hirono married Leighton Kim Oshima, who had a child from a previous marriage.
United States Senate, one of the two houses of the legislature (Congress) of the United States, established in 1789 under the Constitution. Each state elects two senators for six-year terms. The terms of about one-third of the Senate membership expire every two years, earning the chamber the nickname “the house that never dies.”
Constitutional framework
The role of the Senate was conceived by the Founding Fathers as a check on the popularly elected House of Representatives. Thus, each state, regardless of size or population, is equally represented. Further, until the Seventeenth Amendment of the Constitution (1913), election to the Senate was indirect, by the state legislatures. They are now elected directly by voters of each state.
The Senate shares with the House of Representatives responsibility for all lawmaking within the United States. For an act of Congress to be valid, both houses must approve an identical document.
The Senate is given important powers under the “advice and consent” provisions (Article II, section 2) of the Constitution: ratification of treaties requires a two-thirds majority of all senators present and a simple majority for approval of important public appointments, such as those of cabinet members, ambassadors, and justices of the Supreme Court. The Senate also adjudicatesimpeachment proceedings initiated in the House of Representatives, a two-thirds majority being necessary for conviction.
As in the House of Representatives, political parties and the committee system dominate procedure and organization. Each party elects a leader, generally a senator of considerable influence in his or her own right, to coordinate Senate activities. The leader of the largest party is known as the majority leader, while the opposition leader is known as the minority leader. The Senate leaders also play an important role in appointing members of their party to the Senate committees, which consider and process legislation and exercise general control over government agencies and departments. The vice president of the United States serves as the president of the Senate but can vote only in instances where there is a tie. In the vice president’s absence, the president pro tempore—generally the longest-serving member from the majority party—is the presiding officer of the Senate.
Who were the first women to serve in the U.S. Senate?Discover notable women who served in the U.S. Senate.
Sixteen standing committees are grouped mainly around major policy areas, each having staffs, budgets, and various subcommittees. The chair of each committee is a member of the majority party. Among important standing committees are those on appropriations, finance, government operations, foreign relations, and the judiciary. Thousands of bills are referred to the committees during each session of Congress, though the committees take up only a fraction of these bills. At “mark-up” sessions, which may be open or closed, the final language for a law is considered. The committees hold hearings and call witnesses to testify about the legislation before them. Select and special committees are also created to make studies or to conduct investigations and report to the Senate; these committees cover aging, ethics, Indian affairs, and intelligence.
The smaller membership of the Senate permits more extended debate than is common in the House of Representatives. To check a filibuster—endless debate obstructing legislative action—three-fifths of the membership (60 senators) must vote for cloture. (In 2013 the Senate rule for invoking cloture was reinterpreted to permit cloture by majority vote for debate regarding all presidential nominations except those to the Supreme Court, and in 2017 the rule was similarly reinterpreted for Supreme Court nominations.) If the legislation under debate would change the Senate’s standing rules, cloture may be invoked only on a vote of two-thirds of those present. There is a less elaborate structure of party control in the Senate; the position taken by influential senators may be more significant than the position (if any) taken by the party.
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What is a midterm election?Situated two years into a presidential term in the United States, midterm elections determine who serves in many congressional seats.
The constitutional provisions regarding qualifications for membership of the Senate specify a minimum age of 30, citizenship of the United States for nine years, and residence in the state from which elected.
U.S. senators
The table provides a list of current U.S. senators.
United States Senate, 119th Congress Party totals: Republicans (R) 53; Democrats (D) 45; Independents (I) 2
state
senator (party)
service began
term ends
1Martha McSally was appointed in December 2018 and took office the following month to fill the vacancy caused by the resignation of Jon Kyl, who had been appointed in September 2018 to fill the vacancy caused by the death of John McCain. Mark Kelly won a special election in November 2020 and took office in December.
2Alex Padilla was appointed in December 2020 and took office in January 2021 to complete the term of Kamala Harris, who resigned to become vice president.
3Michael Bennet was appointed in January 2009 to complete the term of Ken Salazar, who resigned to become secretary of the interior.
4Ted Kaufman was appointed in January 2009 to replace Joe Biden, who resigned to become vice president. In 2010 Chris Coons won a special election to complete the term.
5Ashley Moody was appointed in January 2025 to replace Marco Rubio, who resigned to become secretary of state. A special election was scheduled for 2026.
6Kelly Loeffler was appointed in December 2019 and took office in January 2020 to fill the vacancy caused by the resignation of Johnny Isakson. Raphael Warnock won a special election in November 2020 and took office in January 2021.
7Brian Schatz was appointed in December 2012 to fill the vacancy caused by the death of Daniel Inouye.
8William Cowan was appointed in January 2013 and took office in February to replace John Kerry, who resigned to become secretary of state. In July 2013 Ed Markey won a special election to complete the term.
9Tina Smith was appointed in December 2017 and took office in January 2018 to fill the vacancy caused by the resignation of Al Franken.
10Roger Wicker was appointed in December 2007 to fill the vacancy caused by the resignation of Trent Lott.
11Cindy Hyde-Smith was appointed in March 2018 and took office in April to fill the vacancy caused by the resignation of Thad Cochran.
12Peter Ricketts was appointed in January 2023 to fill the vacancy caused by the resignation of Ben Sasse.
13Jeff Chiesa was appointed in June 2013 to fill the vacancy caused by the death of Frank R. Lautenberg. In October 2013 Cory Booker won a special election to complete the term.
14Kirsten Gillibrand was appointed in January 2009 to replace Hillary Rodham Clinton, who resigned to become secretary of state.
15Jon Husted was appointed in January 1996 to replace J.D. Vance, who resigned to become vice president. A special election was scheduled for 2026.
16Ron Wyden was elected in January 1996 to complete the term of Bob Packwood, who resigned in 1995.
17Tim Scott was appointed in December 2012 and took office in January 2013 to fill the vacancy caused by the retirement of Jim DeMint.
18John Barrasso was appointed in June 2007 to fill the vacancy caused by the death of Craig Thomas.
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The Editors of Encyclopaedia Britannica. "United States Senate". Encyclopedia Britannica, 25 Feb. 2025, https://www.britannica.com/topic/Senate-United-States-government. Accessed 1 May 2025.
