Here in heavily Republican central Pennsylvania, Carol Sprecher, a registered Republican who votes like an independent, looked disbelievingly at the television as John F. Kerry finished his acceptance speech. "I'm a little surprised," she said. "I kind of liked him."

Ed House, a Democrat watching Kerry in the suburbs of Portland, Ore., said Kerry seemed a bit stiff but more competent on complex issues than President Bush, whom House supported in 2000. "I would rather have someone remote and competent," he said.

Doug Maldonado, a Coast Guard crewman in a noisy Veterans of Foreign Wars post in Miami, seemed disengaged until Kerry called for equality for women and minorities. That grabbed him. "Why? Because I'm a minority," said Maldonado, a Mexican American.

The reactions weren't rousing, but they're just what the Kerry campaign wanted from one of the most coveted constituencies in America. Sprecher, House and Maldonado are undecided voters in states so closely divided that both Kerry and Bush consider them winnable. With the electorate sharply divided, the small fraction of voters who have yet to pick their candidate -- 6 to 10 percent in most polls -- could swing the election in as many as 18 states, and nationally, analysts say.

Washington Post reporters watched Kerry's speech Thursday night with about two dozen undecided voters in three states and at least among that small sampling, the Democrat clearly helped himself.

The men and women, selected unscientifically, began the evening seriously concerned about Bush's handling of the Iraq war but unsure that Kerry could be a commander in chief. When it ended, they all said they liked what they saw and now will consider him seriously as a candidate -- although none said he closed the deal.

Among eight Lancaster voters who watched the speech at a student center at Franklin & Marshall College, Kerry began with no outright supporters -- only a widespread disaffection with Bush that made them hungry for an alternative. None said they felt they knew "who Kerry is as a person," as Ronnie Burgess, 36, a travel counselor for AAA, put it. And they all said they had been affected by seeing numerous Bush campaign ads portraying Kerry as a flip-flopper.

But Kerry seemed to reach them almost as soon as he took the podium. They laughed at his joke of having been "born in the west wing" of a Denver area hospital. Three of the six women applauded when he pledged to fight for "full equality for all women." Sprecher, a sales and marketing representative whose son-in-law was denied release from the Army Reserve two years ago and is due to go to Iraq in January, exclaimed "Thank you!" when Kerry vowed to "end the backdoor draft" of National Guard members and reservists. And Alim Kamara, 31, a social studies teacher, clapped loudly when Kerry said he would name an attorney general who upholds the Constitution.

All said they were impressed with Kerry's national security credentials, but they talked more about domestic issues. Kathryn Paolilli, 46, a mother of four who voted for Bush in 2000, said her main complaint about the president is his infusion of Christianity into politics. She smiled widely and nodded when Kerry said: "I don't want to claim that God is on our side. As Abraham Lincoln told us, 'I want to pray humbly that we are on God's side.' "

Kerry's many references to struggling middle-class families struck a chord with all the Lancaster voters. They are solidly middle class, but most said they are losing ground financially -- Sprecher recently took a second job, and Burgess said, "I still have my dollars, but they're not going anywhere." And all said health insurance consumes more and more of their income.

The five black voters in the group were enthusiastic about the nominee's strong statements against discrimination. But Orlando Cleaves, 33, a bank manager who is a Democrat, said he does not trust what he hears from politicians, particularly since the 2000 election. "That turned me off because I voted and my vote didn't count," said Cleaves, who voted for Al Gore. "So Kerry said a whole lot, but it's what you want to hear."

The voters seemed not to lose interest throughout the 55-minute speech, watching Kerry's body language as well as his face. Burgess said she could tell Kerry loves his wife, Teresa Heinz Kerry. Paolilli said she was impressed that he hugged his former crewmen.

Paolilli also said Kerry made her feel that she had a role to play as a citizen. "He seemed to be saying we all have to make this happen. Give me a shovel. I want to dig," she said. "With Bush, it's like he's going to take care of it and we're supposed to go about our business."

If the Lancaster voters take Kerry more seriously, they still have doubts. "He didn't explain how he'd do all these things," said Kristin Timanus, 24, a youth services coordinator.

"Do we trust this guy? I don't know," said Tricia Cleaves, 31. "I'm willing to hear what Bush has to say."

In Oregon . . .

Fifteen voters sat in rapt silence in a garden apartment and sponged up Kerry's spiel. When it was over, even the Republicans in the room agreed that the Democratic presidential nominee had done himself a world of good.

Sure, he was stiff -- they struggled not to laugh when Kerry, like Dudley Do-Right in a dark suit, saluted the convention and said he was "reporting for duty." But they agreed that he came across as sincerely stiff.

The surprise, they said, was Kerry's energy.

"He is not supposed to be full of energy," said Greg Maurer, 37, an intellectual-property lawyer and a Catholic Republican from a military family. "He was energizing me. I felt like I need to go out and do something for the country."

Maurer voted for Bush last time and said he would probably vote for him again -- yet Kerry's speech planted seeds of doubt. "You could picture him in the White House, and we would be proud he was there," Maurer said. "I never had that image of him before."

For this group the foreign policy issue that dominated Kerry's speech -- war in Iraq -- also dominated their reaction to it.

"I feel like we were misled going into the war," said House, 56, head librarian at Beaverton Library. Kerry's frequent references to his military service in Vietnam went down well with him. "He doesn't take war lightly."

In presidential salesmanship, there is only so far any candidate can go in a single speech before he risks sounding ridiculous, the voters said.

"Look at [former Vermont governor Howard] Dean and his weird speech in Iowa and what it did to him," said Melissa Hardin, 24, a flight attendant who is a registered Democrat. She voted for Gore in 2000.

Kerry, she said, succeeded in selling himself as a smart, not-too-negative alternative to Bush -- and he did it without sounding like a touchy-feely phony. "If he had come out and said 'Ooh, hug me,' it wouldn't have worked," she said.

. . . And In Florida

The South Beach VFW post -- an "only in Miami" kind of place at the base of a 33-story hipsters' condominium complex -- frowns on partisan displays, so Phyllis Garcia left her "Vote John Kerry" button at home. But when the Democratic nominee talked about insurance company bureaucrats making medical decisions, Garcia couldn't contain herself.

"That's true," she called out from behind the bar, where she volunteers.

"Yay, yay," she yelled, bouncing on her toes. "Yay!"

The room, like much of America, was filled with people who have made up their minds: Firm Bush supporters. Firm Kerry supporters.

But when Kerry spoke of Republicans and Democrats working together, Mike Dougherty, a Marine gunnery sergeant at the U.S. Southern Command, folded his arms and shook his head: "It's scripted," he declared.

When Kerry talked of stem cell research and finding cures for AIDS, Jennifer Godfrey, 25, a Coast Guard crew member, rolled her eyes. "Look," she said, "he went from county to county and state to state and found out what people wanted to hear. That's what he's basing his speech on."

Amid the military crowd in the veterans post, party affiliation clearly influenced views of Kerry's emphasis of his service in Vietnam.

"He outdid himself," said J. Doug Morris, 66, the post commander who served in the Army in the 1950s and is an old-line southern Democrat. "He projected that he would be a strong leader of our country."

But Michael Morretti, a Republican and the commander of a Coast Guard cutter, was unimpressed: "He didn't win me over. I'm pretty open-minded. But he didn't win me over."

Harden reported from Beaverton, Ore. Staff writer Manuel Roig-Franzia in Miami contributed to this report.

The Democratic nominee "projected that he would be a strong leader," said J. Doug Morris, a veteran.