New poll shows Obama up by three points in McCain's home state.

    Phoenix - In a sign of continued weakness in his home state, an online poll shows Sen. John McCain trailing Sen. Barack Obama by 3-percentage points in Arizona. The poll also shows the candidacy of Liberterian Bob Barr is having a significant impact on McCain's campaign by siphoning off conservative voters nationwide.

    The Arizona poll was part of nationwide Zogby International poll that put Obama ahead in total electoral votes with 273 to 160 for McCain. The poll found 11 states with 105 electoral votes too close to call -- including Arizona. McCain's campaign in June included Arizona among its list of swing states.

    McCain not only faced problems with Independent voters, he is losing a small, but potentially lethal voting block of the GOP right to Barr. The former Republican congressman from Georgia is pulling just enough voters in many states to shift the balance to Obama. Whether this bloc will remain in Barr's camp on election day could determine the outcome.

    "Barr is hurting McCain all across the country," said Fritz Wenzel, director of communications for Zogby.

    The Zogby poll of 1,142 likely Arizona voters was conducted June 11-30, with a margin of error of plus or minus 3 percentage points. The survey found Obama leading in Arizona with 42 percent of the vote, followed by McCain with 39 percent. Barr had 7 percent, followed by Independent Ralph Nader with 2 percent. Five percent of the voters selected other candidates and 5 percent were undecided.

    Wenzel said 16 percent of Arizona voters who described themselves as very conservative said they would vote for Barr, with 64 percent backing McCain. The double-digit defection to Barr signals further trouble ahead for Arizona's senior Senator.

    "That's very dangerous for a Republican candidate," Wentzel said.

    The poll shows Obama crushing McCain among Arizona Independent voters, 51 percent to 28 percent. The number of Independent voters in Arizona has skyrocketed in the last year and now makes up 27 percent of the state's voters. Republicans continue to hold a narrow 38 percent to 34 percent lead over Democrats in registered voters.

    The McCain campaign did not return a call this afternoon from The Washington Independent for comment on the poll. The Arizona Republic reported Thursday that McCain's campaign called the Zogby poll a "fraud" and questioned the methodology of Internet polling. "John McCain has won every campaign he has run in Arizona, and he will win in November," Kurt Davis, Arizona McCain '08 co-chairman, told the newspaper.

    John Zogby, president and chief executive officer of Zogby, said the poll was a scientific survey of voters likely to participate. "This is, for the moment, a very useful tool that suggests to me that John McCain has not closed the deal in his home state," Zogby told the Republic.

    Recent polls of Arizona registered voters by traditional pollsters have found McCain leading Obama by about 10 percentage points, with Obama steadily narrowing the gap. In April, McCain led Obama by 20 points. In late June, a Rasmussen Reports telephone survey showed McCain with 49 percent of the vote and Obama with 40 percent.

    A statewide Cronkite/Eight poll of registered voters conducted by Arizona State University in late June found that 38 percent said they would vote for McCain and 28 percent said they would vote for Obama, with 34 percent undecided.

    Traditional pollsters relying on telephone surveys often criticize online polls for their lack of scientific methodology. "Online polls are not being heavily relied upon and are not anything other than folkloric," said Earl de Berg, director of the Phoenix-based Behavior Research Center that conducts the Rocky Mountain Poll. The latest Rocky Mountain Poll conducted in May found McCain with 10-percentage point lead over Obama in Arizona.

    But, de Berg said, if the online poll is properly conducted, it could be a valid measurement. "If their sampling is good, then their numbers stand on their own right," he said.

    Wentzel said the sampling is carefully controlled to mirror the percentage of voters registered as Democrats, Republicans and Independents. The online survey is followed up with a telephone validation survey of 2 percent of the online respondents. Strict controls are also employed to prevent survey participants from voting multiple times under different names. "It's highly controlled," Wentzel said, "and it's a very scientific process."

    Wentzel said the significant difference between the Zogby poll showing Obama leading Arizona while other polls have McCain up by about 10 percentage points can be attributed to Zogby's focus on likely voters as opposed to registered voters.

    Wentzel said the national race remains close even though the survey shows Obama winning 273 of the 270 electoral votes needed to win. "It's way too close to make any conclusive remarks about who is going to win this election," he said. "But it is clear that Obama is not only holding his own in key Democratic strongholds, but he is making inroads into traditional Republican areas."