BOSTON (AP) — There will be a Kennedy in Congress again as Democrat Joseph Kennedy III defeated Republican businessman Sean Bielat in the race to replace retiring Democratic Rep. Barney Frank.
The 32-year-old Kennedy is the first of his generation in his famous political family to seek elected office.
The Brookline resident is the grandson of Robert F. Kennedy and son of Joseph P. Kennedy II, who represented the state’s 8th Congressional District. He graduated from Stanford University and Harvard Law School, served in the Peace Corps and worked as a prosecutor.
In 2006, he and his twin brother, Matt, managed the final U.S. Senate campaign of their great-uncle Edward Kennedy, who died in 2009.
Kennedy will represent the 4th District, extending from the Boston suburbs of Newton and Brookline to part of Fall River in the south.
In his speech to supporters Tuesday, Kennedy called his victory an ‘‘incredible moment’’ and praised Bielat, who also ran unsuccessfully against Frank two years ago, for a hard-fought race. He paid homage to Frank, who represented the district for more than three decades.
‘‘I promise that I will do everything I can to pick up the mantle where you left off,’’ he said.
From the start, Kennedy showed an impressive ability to raise campaign money, with the help of family connections. He had raised more than $4 million for his campaign, according to the most recent figures from the Federal Election Commission.
Kennedy’s total was more than twice that of any incumbent House Democrat from Massachusetts and was more than four times the amount raised by his Republican opponent.
While Kennedy often stated that he was proud of his family background, he also insisted that he would earn every vote in the district. The district was changed considerably during the latest round of redistricting, which resulted in the loss of one of the state’s 10 current House seats. For example, New Bedford, a Frank stronghold, was moved to the new 9th District.
The election returns a Kennedy family member to public office in Washington after a brief two-year hiatus. At least one Kennedy had served in Congress or the White House from 1946 through 2010, when former Rep. Patrick Kennedy, of Rhode Island, chose not to seek re-election.
Bielat, 37, thanked his supporters for their effort.
‘‘We ran the campaign we wanted to run,’’ he said.