SPRINGFIELD, Mo. — Democratic presidential contender Barack Obama said yesterday that his Republican rival, John McCain, "thinks we're on the right track," drawing a chorus of boos from a swing state audience vocal about the status quo.

"These anxieties seem to be growing with each passing day," Obama said on a campaign trip in this economically ailing battleground state. "We can either choose a new direction for our economy or we can keep doing what we've been doing. My opponent, John McCain, thinks we're on the right track."

That elicited boos from some of the 1,500 people who filled a Springfield high school gymnasium. When an AP-Ipsos poll asked the "right track, wrong track" question this month, 77 percent said they thought the country was on the wrong track. The same poll set President Bush's approval rating at 28 percent. Both were records for the AP-Ipsos survey.

"We don't need the same old tired answers," Obama said. "We need something new."

Obama said McCain will resort to tired Republican charges that he's a big-spending liberal, arguing his tax-cut plans are aimed at the middle class.

"I want to cut taxes for middle-class families, ordinary folks who are working hard and playing by the rules," he said.

He compared himself to Wild Bill Hickok, who he said fought a duel in Springfield.

"I'm ready to duel John McCain on taxes right here, quick draw," Obama said. That drew a quick retort from a McCain aide.

"If Barack Obama wants this so-called duel then why did he and his entourage run for the hills when John McCain challenged him to 10 town halls?" said McCain spokesman Tucker Bounds.

Obama spent the day riding a bus across southwest Missouri, where Republicans have triumphed in recent elections. He faces the challenge of convincing voters in rural sections of the country to back his campaign.

"It's a leap, electing a 46-year-old black guy named Barack Obama," he said at one point.