By John Whitesides, Political Correspondent
"What they're going to do is make you scared -- of me," Obama told voters in Springfield, Missouri, as he pushed his message of middle-class economic relief in a Republican part of a key battleground state in November's presidential election.
"'He's not patriotic enough. He's got a funny name. He doesn't look like all the presidents on the dollar bills,'" said Obama, who would be the first black U.S. president.
McCain launched a new ad linking the Illinois senator to celebrities like Britney Spears and Paris Hilton, calling him "the biggest celebrity in the world" but questioning whether he could deliver on his talk.
"Senator Obama doesn't have the strength to speak openly and directly about how he will address the serious challenges that confront America," McCain said. "How will he be strong enough to really change Washington?"
McCain campaign manager Rick Davis told reporters Obama's overseas swing was "much more something you would expect from someone releasing a new movie than running for president."
He said the Obama strategy was to develop a fan base "that allows him to get a lot of media attention and avoids him having to address the important issues of our time."
"I don't pay attention to John McCain's ads, although I do notice he doesn't seem to have anything very positive to say about himself," Obama told reporters after visiting a diner in Lebanon, Missouri.
Obama has pivoted to economic themes this week after returning from his trip to the Middle East and Europe, painting McCain as a follower of President George W. Bush's "reckless" economic policies.
"Let me tell you, I know this man. He is humble, he is devoutly Christian, he loves his family more than anything else in the world, he reveres our men and women in uniform, and he is as red, white and blue as you can possibly get," she said.