Kennedy, the eldest son of former Sen. Robert F. Kennedy, made the announcement at the offices of Citizens Energy Corp., a heating firm which he founded and took over again upon the death of his younger brother, Michael, in a December ski accident.
In addition to Michael's death, Kennedy also cited his desire to spend more time with his wife, Beth, and his twin sons from his first marriage.
"This last year has brought me new recognition of our own individual vulnerabilities and the vagaries of life," Kennedy said. "I want to focus as well on responsibilities to my own family, both my immediate family and the larger one."
Kennedy said he would devote his energies to his heating company, but that he did not rule out running again for political office.
Quoting his uncle, the late President John F. Kennedy, he called public service "an honorable profession."He cited in his resignation his work on issues such as health care, affordable housing, Social Security, Medicare and educational opportunity.
A six-term Congressman, Kenendy represents the 8th District, which covers much of Boston and Cambridge. It is the same seat once held by his uncle, the late President John F. Kennedy, and by the late House Speaker Thomas P. "Tip" O'Neill Jr.
U.S. Rep. Marty Meehan, D-Lowell, said the battle to succeed Kennedy would be a "real fight."
"That's a very politically active district," he said. "It will be a heck of a race."
Meehan said he could envision Senate President Thomas Birmingham, D-Chelsea, running as well as former Sen. George Bachrach and Sen. Warren Tolman, D-Watertown, who is currently running for lieutenant governor.
When he abandoned the gubernatorial candidacy in August, Kennedy said at the time that he planned to seek a seventh congressional term in 1998. Still, political watchers speculated that Kennedy might leave Congress for the private sector, seek a job in the Clinton administration or even jumpstart his one-time gubernatorial aspirations.
Kennedy, who was 15 when his father was assassinated in 1968, won overwhelmingly in each election for Congress since 1986.
Kennedy, a member of the House Banking & Financial Services Committee, cited in his resignation his work on issues such as health care, affordable housing, Social Security, Medicare and educational opportunity.
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