WASHINGTON -- Sen. Edward M. Kennedy will be a tough act to follow, even for the Kennedys. His death, coupled with the decision by family members not to seek the seat he held for nearly five decades, has prompted predictions that the family's long-running political dynasty is over.

There's talk the Kennedy political bloodlines are running thin. Some say the younger brood lacks the grit and zest for political combat that drove the liberal Democrat to become one of the leading politicians of the last 40 years.

Yet it's probably too early to write off one of America's most powerful and popular families. A new generation of Kennedys, many of whom are active in humanitarian and political causes, could emerge to extend the dynasty.

Among the possibilities:

-- The late senator's eldest son, Edward Kennedy Jr. The Connecticut attorney, 48, said he's considering following in his father's footsteps in politics but has no immediate plans to do so.

-- Former six-term Massachusetts congressman Joe Kennedy, 57, the eldest son of Robert Kennedy. He recently balked at running for his uncle's Senate seat. His congressional background could help if he returns to politics. But his public image was hurt in 1997 after his former wife, Sheila Rauch Kennedy, published a book about their marriage.

-- One of Joe Kennedy's two sons, Joseph Kennedy III. He could seek his father's old House seat if the current holder, Democratic Rep. Michael Capuano, wins the special election to replace Ted Kennedy in Massachusetts.

-- Kathleen Kennedy Townsend, the eldest of Robert Kennedy's 11 children. She was lieutenant governor of Maryland, but her 2002 gubernatorial bid sputtered.

-- Rhode Island congressman Patrick Kennedy. The youngest son of Ted Kennedy has used his struggles with depression and substance abuse to champion better care for the mentally ill, but there are no signs he's eager for a Senate seat.

Other possibilities include the children of the late Eunice Kennedy Shriver, who was founder of the Special Olympics and one of Ted Kennedy's siblings.

Timothy Shriver is chairman and CEO of Special Olympics. Maria Shriver is California's first lady. Anthony Paul Shriver founded Best Buddies International to help people with intellectual disabilities. Mark Shriver, a former member of the Maryland House of Delegates, works for Save the Children.