BOSTON — With polls showing a narrowing gap between President Bush and Senator Kerry, independent candidate Ralph Nader said yesterday that he planned to continue campaigning in key battleground states in the final month of the presidential election.

Mr. Nader, a Winsted, Conn., native, has long disputed the charge that he will be a “spoiler” for the Democrats in November. Critics have said his candidacy cost Vice President Gore the presidential election in 2000 when he lost by just a few hundred votes in Florida, where the liberal Mr. Nader got 97,000 votes for his Green Party candidacy.

While preparing for a campaign trip that begins at Harvard today and continues to the swing states of Maine and New Hampshire tomorrow, Mr. Nader said defeating Mr. Bush is a priority, but he’s still trying to capture as many votes as possible in November.

“The assumption of all these questions is that I take more votes away from Kerry than Bush. Part of that is in Kerry’s hands. He once said he wants to take away my votes by taking away my issues: I’m delivering it to him on a silver platter. He’s responsible for that problem,” Mr. Nader said.

In a Newsweek poll, the first taken since the debate Thursday night, Mr. Kerry was running even with Mr. Bush after having trailed him in the same survey last month. The Newsweek poll showed Mr. Kerry had the support of 47% and Mr. Bush 45%, with Mr. Nader at 2%.

Mr. Bush led 49-43 in the poll in early September and was up by 11 points in the poll following the GOP convention. The Newsweek poll of 1,013 registered voters was taken from late Thursday to early Saturday and has a margin of sampling error of plus or minus 4 percentage points.

Tobe Berkovitz, a political analyst and professor of communication at Boston University, said Mr. Nader’s role could prove pivotal once again in the election.

“Nader is a factor because, in a race that seems to be this close, a point here, two points there in a battleground state can make a real difference in the Electoral College,” he said.

Mr. Nader said that his supporters don’t pull votes from one party or the other. Rather, half of his supporters would not otherwise vote at all, and the other half are split equally between Mr. Kerry and Mr. Bush.

“You never know. Our problem is how to break up the two-party system, not how to concede to one or the other,” he said.

Mr. Nader’s potential swing role for the election spurred a California peace activist to pledge last week not to eat until November 2 in an effort to persuade Mr. Nader to drop out of the race.

“We’re sending him some carrot juice,” Mr. Nader said yesterday.

Yesterday, Mr. Kerry campaigned for votes in Austintown, Ohio, a Democratic stronghold, where he is still struggling to break ahead despite massive job losses under Mr. Bush.

Mr. Kerry has visited Ohio at least 18 times this year, more than any other state, and he returned to Mahoning County to stake claim to what should be solid support. He stumped with union workers and other supporters and then flew to Cleveland to worship at one of the city’s largest predominantly black churches with the Rev. Jesse Jackson.

Mr. Kerry quoted scripture, and although his prepared remarks criticized the president by name, he avoided that while in the church. Still, it was clear Mr. Kerry was referring to the Bush administration when he told the biblical tale of the Good Samaritan, who aided a robbed and beaten man.

“When I look at what has happened over these last four years, these people who talk about doing good, they have crossed over to the other side and they have walked on by,” Mr. Kerry said to a standing ovation. “And it is time for us to have leadership in this country that lifts everybody up.”

Mahoning County went to Democrat Al Gore by 26 percentage points in 2000, but Kerry spokeswoman Jennifer Palmieri said the Democrats there are “mavericks” who are open to crossing party lines.

Ms. Palmieri said the voters in the region are distraught about plant closings and fights with management over cuts to wages and benefits. “They don’t think the president can do anything about jobs,” she said.

Mr. Kerry tried to convince them otherwise with a day of feel-your-pain politicking that started with a doughnut delivery to picketing workers at RMI Titanium in Niles.

“I’m sorry you’re going through it, but help is on the way,” Mr. Kerry said before asking the workers to help his campaign. “Give us a hand.”

Mr. Kerry asked several of the workers for their stories and expressed sympathy as they told of their struggles to make ends meet during a yearlong lockout. “You try to survive,” said Donald Bertleff, 54, a nine-year veteran of RMI. “It’s rough.”

“Tell me about it,” Mr. Kerry said.

Later, Mr. Kerry stood in the middle of the gymnasium at nearby Austintown Fitch High School, working the crowd sitting on all four sides of him like a talk show host taping an episode on the economic struggles of the American family.