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.
"It's true that change is hard, change isn't easy," Obama said. "Nobody here thinks that Bush or McCain has a real answer for the challenges we face so what they're going to try to do is make you scared about me."
Change with difficulty was a core theme Democrat Bill Clinton used when he opposed President George H.W. Bush in 1992, a campaign also fought during tough economic times.
"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 western legend Wild Bill Hickok, who he said fought a duel in Springfield.
"I'm ready to duel John McCain on taxes right here, quick draw," said Obama. 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 responded after shaking hands at a restaurant in Lebanon.
"I don't hear very much positive from Sen. McCain," he said. "He seems to be only talking about me. You need to ask John McCain what he's for not just what he's against."
Obama was spending the day riding a bus across southwest Missouri, where Republicans have been dominant in recent elections, and arguing that he can bring new regions into play this election cycle because a sour economy is dominating the political landscape. He faces the challenge of convincing voters in largely rural sections of the country to back his campaign.
After a weeklong overseas trip to burnish his foreign policy credentials, Obama has been working overtime to focus on the economy and overcoming doubts voters may have about the first black man to make a serious bid for the White House.
"It's a leap, electing a 46-year-old black guy named Barack Obama," he said, adding that the message Republicans have for voters is simple: "He doesn't look like all those other presidents on the dollar bill."
Springfield is represented in the House by Republican Whip Roy Blunt, and its 7th District supported Bush with 67 percent of the vote in 2004.
Obama traveled with Sen. Claire McCaskill, herself a product of rural Missouri. She warmed up audiences by reminding them that Obama was elected in Illinois, a heavily rural state outside of Chicago.
"They said a young black guy named Barack Obama couldn't get elected to the United States Senate from Illinois," McCaskill said. "They were wrong."
Speaking to The Associated Press, McCaskill said there were gains to be made in rural Missouri.
"The idea here is it makes a difference if you demonstrate to people in Republican strongholds that you want their vote and that you care about them," she said. "I don't think any of us on the campaign are anticipating that Sen. Obama is going to win southwest Missouri. The question is how many votes can we get in southwest Missouri."
Obama spokeswoman Jennifer Psaki was blunt in explaining the strategy.
"What we're trying to do is go into areas where people are more skeptical," Psaki said. "You have to go into the belly of the beast."
On the Net: