Struggling to contain an emotional fire his own campaign kindled, Republican presidential nominee John McCain spent much of a town hall meeting in Lakeville on Friday trying to cool his supporters' growing hostility toward Democrat Barack Obama.

Responding to repeated questions about Obama's truthfulness and personal background, McCain urged backers at a packed gym at Lakeville South High School to be "respectful" toward his opponent.

McCain found himself in the odd and uncomfortable position of defending an opponent who is pulling away in many polls at the end of a week when he and running mate Sarah Palin stepped up their own attacks against Obama -- often inspiring outbursts at raucous rallies, complete with cries of "terrorist" and "off with his head."

The Minnesota gathering lacked that kind of harshness, but sustained booing greeted many of McCain's attempts to discourage the crowd's fear and anger. Of the 21 questions posed to McCain during 45 minutes of give-and-take, one-third challenged him to take on Obama more aggressively, with a few making incendiary comments.

Late in the town hall meeting, Gayle Quinnell of Shakopee called Obama "an Arab." Taken aback, McCain shook his head and, taking the microphone from her, said, "No, ma'am. He's a decent family man, citizen that I just happen to have disagreements with on fundamental issues."

After the rally, Quinnell was unrepentant. "You can't trust Barack Hussein Obama because he is a Muslim and a terrorist," she said.

Obama is a Christian.

McCain repeatedly tried to dial down his supporters' antipathy toward Obama. "I will fight, but we will be respectful," he said. "I admire Senator Obama" -- as the crowd booed loudly -- "I want everyone to be respectful. ... I don't mean you have to reduce your ferocity, just be respectful."

Repeatedly, audience members challenged McCain to toughen his rhetoric against Obama, most notably former Sen. Rudy Boschwitz, who told the senator to press "some of the associations" in Obama's past.

Boschwitz was referring to William Ayers, a founder of the violent Vietnam-era group the Weather Underground. Ayers, now a college professor, hosted a meet-the-candidate gathering for Obama when Obama ran for the Illinois state Senate in 1995, and they served together on a charitable board from 2000-02.

"Ayers is an unrepentant terrorist," McCain said. "I don't care about old, washed-up terrorists, but I care about people telling the truth about their associations."

McCain said Obama's "political career was launched in Mr. Ayers' living room."

"We'll be talking about him more," McCain said.

One man, who said his wife is pregnant, told McCain they're "scared, scared of an Obama presidency. We don't want to bring up our child in a country. ... Someone who cohorts with domestic terrorists like William Ayers."

McCain called his opponent "a decent person and a person you don't have to be scared of as president of the United States." More boos. "I'd be a heck of a lot better president."

On the economy

During a 15-minute speech that preceded the question-and-answer session, McCain focused on the economy, saying, "We are struggling. We're in the greatest financial crisis of our lifetime."

He repeated the proposal he made earlier this week for a federal effort to refinance mortgages for struggling homeowners, saying it would address the nation's housing meltdown, which he called "the heart of this crisis." "We need to buy out these bad mortgages."

He said he had warned of the troubled finances of Fannie Mae and Freddie Mac two years ago, pointing out "cronyism and corruption." "Senator Obama didn't lift a finger when we tried to fix this cronyism."

At a rally Friday morning in La Crosse, Wis., McCain pledged to balance the federal budget by the end of his term.

The Arizona senator is in the midst of an Upper Midwest campaign swing that is central to his come-from-behind strategy barely three weeks before Election Day.

Some political analysts expressed puzzlement over McCain's Upper Midwest swing, given that Obama's recent momentum has shrunk the Arizona senator's Electoral College map and polls show McCain trailing in Minnesota, Iowa and Wisconsin.

But the tour - three stops in Wisconsin on Thursday and Friday, followed by the Lakeville event and a rally in Iowa today - provide strong evidence that McCain's strategists believe the states remain winnable.

Both campaigns have ramped up their efforts in the three states because their relatively similar demographics and overlapping media markets mean the candidates can make a bid for the states' combined 27 electoral votes. That represents a prize bigger than the battleground states of Ohio or Florida.

One indication of the states' importance is the fact that McCain, Obama or their running mates have visited them more than a dozen times in just over a month. And Obama's wife, Michelle, will return to Minnesota on Monday.

Another indication of the competitiveness in the region is the fact that the two campaigns have spent $3 million to air more than 6,000 ads on Twin Cities television stations since the beginning of the year, the Associated Press reported. Overall, McCain has heavily outspent Obama,

Staff Writer Pat Doyle contributed to this report. Bob von Sternberg • 612-673-7184