By Noreen O'Donnell
NEW YORK (Reuters) - U.S. Senator Frank Lautenberg, whose death has sparked a battle over his seat in the Senate, was remembered at his funeral on Wednesday as a tenacious fighter who battled tirelessly for the causes he championed.
Vice President Joe Biden eulogized Lautenberg, a fellow Democrat who died on Monday at age 89, as having "both physical courage and moral courage."
Lautenberg was the Senate's oldest member and its last surviving World War Two veteran. He died of complications from viral pneumonia.
"He never gave up. He never gave in," Biden said. "Frank always had to be in the game."
Scores of dignitaries filled the Park Avenue Synagogue for the service, including some of the politicians jockeying for position in the power play sparked by Lautenberg's Senate seat coming vacant.
Among them was New Jersey Governor Chris Christie, a Republican seeking re-election and a possible White House contender in 2016, who has called a special election on October 16 to fill the seat.
Also on hand was Newark Mayor Cory Booker, a rising star in the Democratic Party who has expressed interest in the seat.
Former U.S. Secretary of State Hillary Clinton recalled that Lautenberg fought for veterans, victims of HIV and AIDS, families trying to keep their children safe from toxic chemicals and "stood proudly with the working people of New Jersey trying to provide for their families, to build businesses like Frank and his two friends had, to pursue the American dream.
"As Frank would say, 'It's not where you sit that counts. It's where you stand,'" Clinton said. "There was never any doubt where he stood."
Family members offered up warm and funny reminiscences, describing him as stubborn, with a ceaseless need to be right and regret over his decision to retire at the end of 2014.
They described how he grew up poor in Paterson, New Jersey, where his immigrant father worked in a silk mill, fought in Europe in World War Two, graduated from Columbia University and co-founded the payroll services company Automatic Data Processing.
New Jersey voters elected the self-made multimillionaire to five six-year terms in the U.S. Senate, where he battled on behalf of smoking bans, gun control, airline safety and rail transportation.
First elected in 1982, he left office in 2000, saying he was tired of raising money for his campaigns. But two years later he came out of retirement when former Senator Robert Torricelli was forced to drop his re-election bid amid corruption charges.
The controversy over replacing Lautenberg in the Senate started almost immediately after his death when Christie on Tuesday called the special election and said he would appoint a replacement until then within the week.
Christie's own political aspirations were seen to be at stake in his decision. Democrats accused him of self-interest and wasteful spending by staging the special election just three weeks ahead of the November 5 general election, when he is seeking re-election.
They say he should have scheduled both contests on the same day but that he was avoiding being on the same ballot as Booker, who could attract both strong Democratic and minority turnout.
If Christie wins the governorship by a large margin, he could position himself as a Republican who can win other Democratic states.
Christie could have chosen a replacement to fill Lautenberg's seat through 2014, but any pick posed political danger.
A conservative choice would have pleased Republicans angry over Christie's close working relationship with President Obama in the wake of Superstorm Sandy but could have endangered Christie's standing with Democrats in his home state.
However, some Republicans were angered that Christie opted not to fill the seat for longer, costing their party what could have been a hold on it for more than a year and a half.
The balance of power in the Senate is now held by Democrats, 54-45, with one vacancy.
A primary election on August 13 will decide the Republican and Democratic nominees for the October special election.
(Editing by Barbara Goldberg, Ellen Wulfhorst, Grant McCool and Dan Grebler)