"I think it's too early to declare victory, because Barack Obama is black," Gergen said Tuesday night. "And until we play out the issue of race in this country, I don't think we'll know and maybe (not until) late in the campaign."

While Obama's campaign has fended off racially rooted attacks since its inception, analysts say the ones surfacing in the past few days have been more overt, arriving as many undecided voters are making their final decision. They are part of a recent stream of attacks on his background, including his religion and his connections to a former '60s radical.

"It is the Willie Hortonization of Obama," said University of San Francisco associate professor of political science James Taylor. Horton, an African American man, was a Massachusetts felon who committed a rape and armed robbery while on a weekend furlough. Republican strategist Lee Atwater used a TV attack ad featuring Horton to create a negative impression of the 1988 Democratic nominee, former Massachusetts Gov. Michael Dukakis, in the campaign's final months.

Instead of using a grainy photo of a grizzled convict as Atwater did, the current attacks, analysts say, are embedded in "coded" language. They cite as examples Republican vice presidential nominee Sarah Palin portraying Obama as a cultural outsider and friend to terrorists and the dismissive way his Republican opponent, Sen. John McCain, referred to Obama at their Tuesday night debate as "that one."

Other recent attacks include the unsubstantiated allegation on Fox News' "Hannity's America" Sunday that Obama's community organizing work in Chicago was "training for a radical overthrow of the government." The incendiary allegations - as well as the anti-Semitic background of the source of the allegation, commentator Andy Martin - went unchallenged and undisclosed by the host, conservative commentator Sean Hannity. Fox said that the program is the host's opinion, even though the allegation was presented as a documentary. Obama did not respond to Hannity's request for comment.

Martin wrote on his blog that "I am not a 'reporter' assembling facts for a morning newspaper. I am an analyst and expert opinion columnist. I take 'facts' that may or may not make sense in isolation, and I analyze them until patterns emerge and conclusions are apparent."

Then there have been the speakers at McCain-Palin rallies who continue, unchecked by the candidates, to refer to "Barack Hussein Obama" - the emphasis on his middle name is an implication that Obama, who is a Christian, is Muslim. The latest occurred Wednesday in Pennsylvania, when Bill Platt, the Lehigh County Republican chairman, mentioned Obama's former reluctance to wear an American flag lapel pin and said: "Think about how you'll feel on Nov. 5 if you see the news that Barack Obama, Barack Hussein Obama, is president of the United States."

McCain-Palin spokesman Paul Lindsay said, "We do not condone this inappropriate rhetoric, which distracts from the real questions of judgment, character and experience that voters will base their decisions on this November."

Regardless, some attending McCain-Palin rallies are responding to this kind of incitement. The Secret Service is investigating press reports that someone might have said "kill him" after Palin tried to connect Obama to former Weather Underground leader Bill Ayers. Some attending McCain's rally Wednesday in Pennsylvania interrupted him with shouts of "socialist," "terrorist" and "liar."

Earlier this week, Palin told a group of donors in Colorado that "this is not a man who sees America like you and I see America." Obama, Palin said, "is someone who sees America, it seems, as being so imperfect, imperfect enough, that he's palling around with terrorists who would target their own country," a reference to Obama's connection with Ayers, now a professor at the University of Illinois at Chicago. Conservative talk radio show host Rush Limbaugh echoed this attack by referring to Obama's "mentorship" by Ayers; Obama was in elementary school when Ayers and the Weather Underground were carrying out bombings.

Politico.com described Obama's relationship with Ayers: "There's no evidence their relationship is more than the casual friendship of two men who occupy overlapping Chicago political circles and who served together on the board of a Chicago foundation." FactCheck.org, a nonpartisan fact-checking organization, confirmed that description.

And during the week of Sept. 28-Oct. 4, "nearly 100 percent of the McCain campaign's advertisements were negative," according to the nonpartisan Wisconsin Advertising Project. "During the same period, 34 percent of the Obama campaign's ads were negative."

Democratic vice presidential nominee Sen. Joe Biden worried Wednesday that the Republicans are injecting "fear and loathing" into the campaign.

"The idea that a leading American politician who might be vice president of the United States would not just stop midsentence and turn and condemn that - it's just a slippery slope, it's a place that we shouldn't be going," Biden said Wednesday on NBC's "Today" show, referring to the shouts of "terrorist" at Palin's rallies.

"I mean, here you have out there these kinds of, you know, incitements out there - a guy introducing Barack using his middle name as if it's some epithet or something," he said on CBS Wednesday. "This is over the top."

These attacks are no different from the kind Atwater - the political mentor of Karl Rove - launched during the 1980s, said Stefan Forbes, director of the documentary "Boogieman: The Lee Atwater Story," which opens Friday in San Francisco.

"I don't see how the Democrats don't understand the Lee Atwater playbook. His tactics have been winning elections, even after his death" in 1991, Forbes said. The Horton campaign "represented the triumph of spin and smear over the issues. They know that if you wrap things in the flag, you can sell anything."

The key to Atwater's success was that the candidates themselves remained above the fray.

"They were friendly, like (Ronald) Reagan," Forbes said. "Just like now, Palin is the friendly face, or George W. Bush was the guy you wanted to have a beer with. They'll dance around it and say (these tactics) aren't racist, but they are.

"The next couple of weeks are going to be really fascinating," Forbes said. "If the Atwater playbook can destroy Obama when the economy is collapsing the way it is, then it can accomplish almost anything."

But Stanford University political science Professor Paul Sniderman, who recently completed a survey on racial attitudes of voters, doesn't think the attacks will work. He also said widely circulated media reports that said "Obama's support would be as much as 6 percentage points higher if there were no white racial prejudice" were wrong.