Washington - Barack Obama's support from backers of Hillary Rodham Clinton is stuck smack where it was in June, a poll showed on Tuesday, a stunning lack of progress that is weakening him with members of the Democratic Party in the close US presidential race.
An Associated Press-Yahoo News poll shows that among adults who backed his rival during their bitter primary campaign, 58 percent now support Obama. That is the same percentage who said so in June, when Clinton ended her attempt and urged her backers to line up behind the Democratic senator from Illinois.
The poll shows that while Obama has gained ground among Clinton's supporters - 69 percent view him favourably now, up 9 percentage points from June - this has yet to translate into more of their support.
In part, this is because their positive views of Republican presidential nominee John McCain have also improved during this period.
Those supporting McCain have also edged up from 21 percent to 28 percent, with the number of undecided staying constant, the survey showed.
Clinton backers' reluctance to support Obama helps explain why he is having a tougher time solidifying partisan supporters than McCain.
Overall, 74 percent of Democrats say they will vote for Obama, compared with 87 percent of Republicans behind the Arizona senator. About nine in 10 Clinton supporters are Democrats.
The problem that supporters of Clinton, the New York senator, have with Obama seems to flow from their measure of him as a candidate, not from issues.
From establishing a timeline for a US withdrawal from Iraq to abortion to cancelling tax cuts on the rich, their views of the importance of issues are virtually identical to Democrats in general.
Yet they find Obama less likable, honest, experienced and inspiring than Democrats overall do, and have a better view of McCain.
And while majorities of Clinton supporters say Obama shares their values and understands ordinary Americans, they're less likely to say so than Democrats overall.
"It's just a gut feeling, my gut tells me he's not it," Leslye Burgess, 53, a federal treasury department manager and Democrat from Fairfax, Virginia, said of Obama. The Clinton supporter added, "I'll have to fight with myself between now and November" about how she'll vote.
The Republican's selection of Sarah Palin as McCain's running mate has had no net impact on Clinton loyalists - a group Republicans were hoping to lure by picking the Alaska governor.
Twenty-one percent in the poll said Palin on the ticket makes them likelier to back McCain, 21 percent said it makes them less likely, and 58 percent said it had no impact.
The choice of Joe Biden as Democratic vice-presidential candidate makes them a bit likelier to vote for Obama, but seven in 10 said it won't be a factor.
Other September polls have shown Obama making progress in recent weeks with one-time Clinton backers and doing better with them than in the AP-Yahoo News survey.
One by the nonpartisan Pew Research Centre had Obama with 78 percent of their support and McCain with 18 percent another by ABC News and The Washington Post showed Obama ahead 72 percent to 23 percent.
Those figures measured Clinton supporters who are registered voters - who in the AP-Yahoo News poll leaned toward Obama over McCain 61 percent to 26 percent. The discrepancies in the polls might come from how they were conducted.
Obama spokesman Bill Burton said Clinton supporters are turning to Obama "in huge numbers" and noted that the AP-Yahoo News data differed from other polls.
He said strong feelings by Clinton supporters were understandable considering the length and intensity of the Democratic primaries and said of Clinton, "She's done everything we've asked her to do."
Clinton spokeswoman Kathleen Strand said the New York senator has campaigned in or planned to visit seven tightly contested states.
Asked to explain why some of her supporters still oppose Obama, Strand said, "She's going to continue to do whatever she can to convince everyone, no matter who they supported, that Barack Obama must be our president."
The AP-Yahoo News poll has surveyed the same nationally representative group of about 2 000 adults seven times since November, in an effort to understand how individuals are reacting to the presidential race.
Nine in 10 Clinton supporters who said in June they were backing Obama were still with him in September, while three-quarters of those with McCain stayed with him.
As during her primary battle against Obama, Clinton supporters are likelier to be female, white and less educated than those who did not back her.
They trust Obama more than McCain on important issues, though not by as much as Democrats overall do. They prefer Obama over McCain on the economy by 30 percentage points, compared with Obama's 50-point edge among all Democrats. They like Obama on Iraq by 17 points, while all Democrats give Obama a 40-point margin.
The starkest contrast comes from comparing Clinton backers still refusing to support Obama with other Democrats.
Just three in 10 Clinton supporters still not backing Obama view him favourably, compared with eight in 10 of all Democrats. While most Democrats and former Clinton supporters strongly prefer Obama over McCain to handle key issues, those Clinton voters still opposing Obama opt for McCain: On the economy by 32 points, and on Iraq by 47 points.
One in four Clinton backers say they've not yet locked into a candidate -and far more of those supporting Obama than McCain say they support their candidate strongly. Many who have already decided to back Obama say the transition wasn't difficult.
Kathy McVeigh, 60, a nurse from Norwalk, Ohio, has moved from Clinton to Obama and said she would tell wavering Clinton voters "to get on the bandwagon because we need change, we better do something in a hurry because we're going down the tubes."
The AP-Yahoo News poll of 1 740 adults was conducted September 5-15 and has an overall margin of sampling error of plus or minus 2,3 percentage points.
It included interviews with 502 people who in AP-Yahoo News polls in January and April identified themselves as supporting Clinton in one or both of those months, for whom the margin of sampling error was plus or minus 4,4 points.
The survey was conducted over the Internet by Knowledge Networks, which initially contacted people using traditional telephone polling methods and followed with online interviews. People chosen for the study who had no Internet access were given it for free.
In contrast, the Pew and ABC-Post polls relied on people saying in September whether they supported Clinton earlier in 2008.
Those polls were conducted by telephone some studies have shown people can be less reluctant to disclose embarrassing behaviour - like not supporting their party's presidential nominee - in an online survey than to a live telephone interviewer.
On the other hand, people in the AP-Yahoo News poll who backed Clinton in earlier waves of the survey might not want to appear inconsistent by suddenly backing a candidate - Obama - they opposed earlier. - Sapa-AP