Updated

Sen. John Kerry said Wednesday he would take up one of Sen. Edward Kennedy's key political fights, pledging to the thousands who attended his town hall meeting to push for the health care overhaul championed by his longtime Democratic colleague.

More than 2,000 people turned up for Kerry's first public meeting since Kennedy's Aug. 25 death from brain cancer at age 77. A line of supporters and opponents of health care reforms snaked out of the Somerville high school and down two blocks.

Kerry quickly invoked Kennedy's memory and promised to push for the best health care reform package possible.

"That means taking on these battles in the way that Teddy would and I pledge to you that I will," he said.

Kennedy had repeatedly called the expansion of health care to uninsured Americans the signature issue of his 47-year tenure in the U.S. Senate. Supporters have said his absence in Washington over much of the past year has made the job of hammering out compromise legislation more difficult.

Kerry, also a strong supporter of overhauling the health care system, has vowed to push through the measure in Kennedy's name. He said he would follow Kennedy's example of fighting hard for his principles and seeking political compromises that serve national interest.

"It's very important for us to fight the fight, push as hard as we can for the things that we believe in, stand up for our principles, and if we can't find the votes based on that battle, then we have to find a way to get done the best we can do for the American people," Kerry said.

U.S. Rep. Michael Capuano, a Democrat who represents Somerville and also supports overhauling the nation's health care system, joined Kerry at the town hall.

Capuano is one of several potential candidates for Kennedy's seat. A special election to replace Kennedy is scheduled for Jan. 19, although state lawmakers are considering a bill that would allow Gov. Deval Patrick to appoint someone to the seat on an interim basis during the campaign.

"Every person in Massachusetts wants to do everything we can to make sure every single American has a decent, affordable health care plan," Capuano told an estimated 400 people gathered in the school auditorium for the meeting and an additional 2,000 in overflow rooms.

The meeting was largely free of the rancor and raucous moments that have defined many other town hall meetings this summer. The crowd appeared largely in favor of health care changes, giving Kerry loud cheers whenever he discussed the issue. Those booing appeared to be in the minority.

Kerry at times found himself on the defensive against those in the crowd who said he should push harder for a single-payer system, or at the very least refuse to back a plan that doesn't include a strong public health insurance option.

Kerry said there wasn't enough support in the Senate for a single payer plan under which the government would pay health care bills.

"We do not have 60 votes," he said. "We don't have that critical mass right now to get that done."

Kerry also conceded that passing a plan that includes a public health insurance option will be tough. "We are going to have a very difficult time on the public option debate," he said.

Sylvia Walker, 58, was one of those pressing Kerry for a single-payer or public health insurance option. Walker said she is currently unemployed and spends nearly a quarter of her income on insurance and said a government run program could be more efficient than private insurance.

"Their profit margins are astronomical," she said. "They are taking so much money that could be going to health care."

Anger at the overhaul plan has erupted at recent town hall meetings hosted by members of Congress across the country, including one two weeks ago hosted by Rep. Barney Frank, D-Mass. The congressman chided one critic who held up an image of President Barack Obama with a Hitler-style mustache.