Barack Obama has won endorsements from a former Clinton administration official and two ex-senators, boosting his campaign for the Democratic presidential nomination ahead of Tuesday's Pennsylvania primary that could determine whether rival Hillary Rodham Clinton stays in the race.
The support comes as a new Associated Press-Yahoo News poll shows that Democratic voters now favour Obama over Clinton as their best chance for winning the White House.
A Newsweek poll, also released on Friday, showed Obama ahead among Democratic voters 54 per cent to 35 per cent, marking a big shift from the magazine's last survey in March when he and Clinton were virtually tied.
In a blow to Clinton, Robert Reich, who served as Labor secretary under her husband, former President Bill Clinton, said in a blog post on Friday that "although Hillary Clinton has offered solid and sensible policy proposals, Obama's strike me as even more so." He was joined by two other Democratic elder statesmen, former Sens. Sam Nunn and David Boren, who will serve as advisers on Obama's National Security Foreign Policy team.
Reich, joins a handful of former Clinton cabinet members, including New Mexico governor and former ambasssador to the United Nations, Bill Richardson, in endorsing Obama. He is a longtime friend of the Clintons.
The poll released Friday shows Obama's positive ratings have climbed. But the survey also found that the prolonged, and often acrimonious nomination fight with Clinton, has exacted a price on him. As they get to know him, more voters are saying he is inexperienced, unethical and dishonest.
The findings paint a dire picture for Clinton as she and Obama head into Pennsylvania, the biggest remaining primary on Tuesday with 158 delegates at stake. Even if Clinton wins, as expected, she is unlikely to significantly reduce Obama's lead in delegates, which now stands at 1,645-1,504.
A triumph of any magnitude for Clinton would instantly establish Indiana on May 6 as her next must-win state, particularly since her aides have privately signaled that defeat is likely in North Carolina on the same day.
Friday's poll comes on the heels of another AP-Yahoo poll this week showing that Republican John McCain has pulled even with Obama and Clinton, even though Democrats had been strongly favored to win the presidency in surveys several months earlier.
A clear majority of Democratic voters say Obama has the better chance of defeating McCain in November, according to Thursday's poll. In late January, before Obama scored 11 straight primary and caucus victories, 56 per cent of Democrats saw Clinton as the stronger nominee, compared with 33 per cent for Obama. Now, Obama leads on that question, 56 per cent to 43 per cent. The most encouraging sign for Obama is that many Democrats who previously saw Clinton as their party's best hope now give him that role. About one-third of them still prefer Clinton, but they have lost confidence in her electability.
Obama's positive ratings have climbed as well as his negatives, while Clinton, widely known since the early 1990s, has been less able to change people's views of her. And when those views have shifted, it has hurt her more than helped.
Still, the poll contains some worrisome signs for Obama. Those rating him as "not at all honest," for example, jumped from 18 percent last fall to 27 per cent in April. It came as he was put on the defensive over incendiary comments by his former pastor. But many holding such views are Republicans or conservative independents who would be unlikely to vote in a Democratic primary or support a Democrat in the fall anyway.
Campaigning in Pennsylvania on Friday, Obama shook hands at a bolt factory and beer bottling company in Erie, the type of white, working class, economically depressed area that has supported the former first lady. Clinton campaigned for Hispanics in Philadelphia, a largely black city expected to go for Obama, before heading out to the more competitive suburbs.
Also on Friday, Clinton took issue with Obama's complaints about questions at their debate Wednesday in Philadelphia. Obama had argued that the questions were unfairly focused on him. "Having been in the White House for eight years and seeing what happens in terms of the pressures and the stresses on a president, that was nothing," she said. "I'm with Harry Truman on this, if you can't stand the heat get out of the kitchen. Just speaking for myself, I am very comfortable in the kitchen."
Obama spokesman Bill Burton replied by pointing out that after another debate in Ohio, Clinton complained that she always got asked the first question.
"Her blatant hypocrisy here is stunning," Burton said. Meanwhile, New Jersey Governor Jon Corzine, a Clinton supporter, said Friday that a loss in Pennsylvania's primary would be a "door closer" for Clinton.