Sen. Barack Obama was busy in Missouri last week, stopping in places like Springfield, Rolla and Union, hardly hotbeds of liberal Democratic voters. The presumptive Democratic nominee was clearly hoping to connect with generally conservative voters in this must-win state. It's a strategy he's likely to follow throughout the general election campaign.

As he has done before, Obama told voters that the GOP would try to scare them away by saying that he "is not patriotic enough," has "a funny name" and doesn't resemble "all those other presidents on the dollar bills."

Obama was hardly expecting to be accused of playing the race card.

But handlers for John McCain, Obama's most likely GOP rival in the presidential election, pounced on Obama's remarks with both feet. McCain's campaign manager, Rich Davis, said in a statement that Obama not only had played the race card but "played it from the bottom of the deck. It's divisive, negative, shameful and wrong."

Davis' comments left some political scientists scratching their heads. They noted that Obama has often quipped about his multicultural background without hearing a word from Republicans.

"This makes you a little suspicious of the Republican outrage," says Karthick Ramakrishnan, a political science professor at the University of California at Riverside. "I question the timing of the reaction from McCain's camp. He can't talk about race directly, so he seems to be using this issue to talk about race in a way to highlight the fears of lots of independent voters who don't want to think Obama will make race an issue."

Andra Gillespie, a political scientist at Emory University, says Obama had little choice but to discuss the role of race in the campaign.

"Was he playing the race card? Not in the traditional sense. He was trying to prepare voters for what to expect. He was trying to talk about race" to diffuse the issue, she says.

She adds that Obama's opponents, rather than Obama himself, has done the most to raise the issue of race by talking about it implicitly. Examples, she said, included calling attention to his middle name and implying that he is Muslim even though he is not.

"He's trying to talk about it explicitly, upfront, so that race won't have the effect that others want it to have," she says.

Political scientists aren't sure whether this fuss about the race card will be a short-term issue.

Some, like Ramakrishnan, suggest that the issue might have the same corrosive, long-term effect that Willie Horton, a black inmate, had in depicting Michael Dukakis as being soft on crime when Dukakis ran and lost against former President George Bush in 1988.

"If McCain talked about race directly, he'd turn off a lot of voters, but he can talk about it in another way," he says. "That's what the Willie Horton issue did by talking about race in the context of crime."

David Hollinger, a history professor at the University of California at Berkeley, suggests that McCain has manipulated Obama's comments for political advantage.

"It's to McCain's advantage to find subtle ways to tell white voters that Obama is different from them," he says.

Now, before the Democratic convention, while he is still relatively unknown by many voters is the time for McCain to try to define Obama, suggested correspondent Cokie Roberts on NPR radio. After the convention, she said, it could be too late.

Louis DeSipio, who teaches at the University of California at Irvine, says the next issue that might have racial overtones will be the choice of running mates.

McCain's pick might have racial overtones if he chooses a vice presidential candidate who is against immigration reform, he says. Likewise, Obama would make an indirect statement about race if he chooses a traditional Democrat, a Southern white male, as his running mate, DeSipio says.

At any rate, some observers say it will be difficult for the two candidates not to talk about race in this presidential campaign since, for the first time in history, a major political party is likely to nominate an African American to head its ticket.