By Daniel Lovering
NEWTON, Massachusetts (Reuters) - Joseph Kennedy III easily won the Massachusetts congressional seat being vacated by the retiring fellow Democrat Barney Frank, becoming the first member of his generation of a storied U.S. political family to hold public office.
Kennedy, grandson of the late Senator Robert F. Kennedy, was virtually assured of victory over Republican Sean Bielat after he defeated two lesser-known Democratic Party rivals in the September primary. The district is solidly Democratic and last elected a Republican in 1944.
"We each want the chance, the opportunity to make the most of what we've got, the chance to build a life we can be proud of," Kennedy told Reuters. "I got into this race because, above all else, I believed that that is the promise this country makes to each and every one of us."
As supporters and family members gathered at a hotel in the Boston suburb of Newton, Kennedy's campaign reported late Tuesday he had captured 62 percent of the vote versus Bielat's 36 percent, with 80 percent of precincts reporting.
Kennedy, 31, is heir to one of America's most storied political dynasties, which also produced President John F. Kennedy and Senator Edward M. Kennedy.
He will fill the House seat being vacated next year by veteran Democratic Congressman Frank, who formerly served as chairman of the House Financial Services Committee.
"Joe Kennedy will be great," Frank said at the event, which was held at the same Boston area hotel where he was married in July in a same-sex ceremony. "What you have is a very able, very committed guy who in addition has that family name which will frankly make him better for the district ... He's going to have a lot of influence."
Before launching his bid for office, Kennedy served as a Massachusetts prosecutor, served in the Peace Corps - founded by his great-uncle President John Kennedy - and worked on the final election campaign of his great-uncle Senator Edward Kennedy of Massachusetts, who died in 2009.
(Reporting By Daniel Lovering, editing by Scott Malone, Bernard Orr)