Updated

President Bush (search) is trusted on national security and seen as a strong leader but vulnerable on job creation; Democrat John Kerry (search) is strong on the jobs issue, viewed as the candidate more caring about ordinary people but vulnerable on national security.

After two weeks and tens of millions of dollars spent by both sides on negative advertising, little has changed in the basic landscape of a very close presidential race, an Associated Press poll found.

Bush was backed by 46 percent of voters, Kerry by 43 percent and independent Ralph Nader (search) by 5 percent, according to the poll conducted for the AP by Ipsos-Public Affairs.

That support remains very fluid, with fewer than 30 percent of voters saying they are strong supporters of each of the candidates.

Margaret Topper, a 76-year-old Republican from Media, Pa., is one of those still mulling her choice.

"I voted for Bush last time, but I'm not sure I will this time," she said. "The war is my problem and the debt we're incurring. But Bush stands up for what he believes and is a strong leader."

One effect of the campaign this winter has been to drive down the personal popularity of both candidates, according to public and private polls. Bush has been hurt by weeks of Democratic campaigning and millions of dollars' worth of advertising by various candidates throughout the winter. More than $17 million in advertising by the Bush campaign in recent weeks helped take the sheen off his Democratic rival. Both have lost some popularity, though more voters see each favorably than unfavorably.

The AP-Ipsos poll looked at the comparative strengths and weaknesses of the two closely matched candidates eight months before the election.

Voters said they trust Bush to do a better job of protecting the country by 58 percent to 35 percent. They trust Kerry to do a better job of creating jobs by 53 percent to 37 percent. Kerry has been emphasizing the job issue in campaign appearances and campaign ads.

Both candidates have been trying to change the subject in recent weeks to more friendly turf — Kerry to jobs, Bush to national security. Jobs are the top issue as far as voters are concerned, according to the poll, while national security trails jobs by about 15 percentage points.

Bush and Kerry are closely matched on some measures like honesty, despite efforts by Bush and Kerry to raise questions about each others' credibility. Kerry has a slight advantage on voters' perception that he cares about people like them.

Bush has a big lead over Kerry, 60 percent to 32 percent, on which candidate is the strongest leader, and almost as big a lead on which one is likely to stand up for what he believes. Bush's advertising accuses Kerry of flip-flopping on Senate votes.

People are evenly divided on which candidate has a vision for the future — highlighting the need for both to spell out thorough plans for the future rather than just criticize the other.