President Bush emerged from his New York convention with a solid lead over Democratic challenger John F. Kerry, strengthening his position on virtually every important issue in the campaign and opening up a clear advantage on many of the personal characteristics that influence voters in presidential elections, according to a new Washington Post-ABC News poll.

For the first time in a Post-ABC News poll this year, a majority of probable voters say they plan to vote for Bush. Among those most likely to vote in November, Bush holds a lead of 52 percent to 43 percent over Kerry, with independent Ralph Nader receiving 2 percent of the hypothetical vote. Among all registered voters, Bush leads Kerry 50 percent to 44 percent.

Among a smaller sample in 19 battleground states, where strategists believe the election will be decided, Bush holds a narrower lead among likely voters, 50 percent to 46 percent. Among all voters in these states, the two candidates are running even.

The survey highlights the damage to Kerry in August and during the Republican National Convention. Bush got a four-point "bounce" in support among likely voters from his convention, about what Kerry received from his convention in July. But in other important ways, the poll suggests that Republicans achieved virtually all their objectives last week in New York, particularly their goal of making Kerry less acceptable to voters.

What will not be known for another few weeks is whether Bush's gains are transitory, as Kerry's were in the immediate aftermath of his convention. The setback to Kerry has generated concern among Democrats about his candidacy, but four years ago, Bush trailed Al Gore by eight points and later 10 points in tracking polls taken by the Gallup Organization in mid-September, and he came back to win the presidency.

In the five weeks since the Democratic convention, Kerry's favorable rating has plunged. Besides a relentless pounding from the GOP, Kerry has experienced attacks on his Vietnam War service from a group of Vietnam veterans, and the Democrat's comments about Iraq have been a source of controversy. Kerry's favorable rating fell from 51 percent at beginning of August to 36 percent among registered voters in the new Post-ABC News poll, while his unfavorable rating rose from 32 percent to 42 percent.

Bush's favorable rating rose slightly to 51 percent, and his overall approval rating rose another notch to 52 percent. An identical percentage of voters said Bush deserves a second term. Strategists in both campaigns have watched Bush's approval rating closely as an indicator of his reelection prospects. That rating fell below 50 percent in May and has been inching back up over the summer. History suggests that Bush will be formidable in November if his approval rating remains in the low 50s, vulnerable if he is in the 40s.

The poll suggests that Bush and the GOP successfully, but perhaps only temporarily, altered the issues agenda since the convention, shifting public attention away from the economy, on which voters have generally given Bush negative marks, to terrorism, an issue on which he has always been stronger.

According to the survey, the proportion that named terrorism as the top voting issue increased from 19 percent immediately before the GOP convention to 25 percent right after. At the same time, the proportion naming the economy and jobs as their top voting issue declined four points to 27 percent. Slightly less than one in five -- 18 percent -- named Iraq as their top issue, unchanged from before the convention.

Bush holds significant advantages over Kerry on who would be best equipped to deal with terrorism, Iraq and taxes and smaller advantages on the economy, education and relations with other countries. Kerry holds narrow advantages over Bush on health care and helping the middle class, and the two are virtually tied on the issue of creating jobs.

Judged on several personal attributes, Bush led Kerry on honesty, leadership, vision, values and personality, and was statistically tied on who understands problems of "people like you."

Since the end of the Democratic convention in late July, the race has flipped, with Kerry moving from a six-point advantage over Bush to a six-point deficit among registered voters. Among likely voters, Bush has gone from a two-point deficit to a nine-point advantage.

The poll shows a gender gap among registered voters: Bush holds an 18-point lead among men while Kerry leads by six points among women.

Young people have led the exodus from Kerry to Bush. Since Aug. 1, Kerry's support among voters ages 18 to 29 has dropped from 63 percent to 49 percent while Bush's share of the young vote has increased to 46 percent -- a 28-point turnaround in five weeks.

Bush improved his standing in all regions except the West. The president has erased a 25-point deficit to pull nearly even to Kerry in the East. And in the South, where the race was deadlocked in early August, Bush leads by 19 points.

Bush also has consolidated his standing with conservatives in the past month, claiming 78 percent of their vote, up nine points since early August. The incumbent's gains have come roughly equally from battleground and non-swing states, the poll found.

The survey also found that opposition to the war in Iraq has moderated somewhat. Less than half -- 45 percent -- say the war was not worth fighting, the lowest that figure has been since March. The proportion saying the United States is bogged in Iraq stands at 54 percent, down 11 percentage points since May.

Slightly more than half -- 52 percent -- said they are confident that the federal government can prevent terrorist attacks, up from one year ago and the best showing since March 2002.

The month-long lull in the Kerry campaign plus problems in its handling of questions on Iraq and his service record have dismayed some Democrats. Two in three voters said Bush has run a good or excellent campaign, but barely half -- 52 percent -- of all voters make the same judgment about Kerry's campaign.

"I feel uncomfortable because he doesn't seem to be trying very hard, like he's given up already," said Kathleen Grant, 66, of West Des Moines, Iowa, a Kerry supporter. "I feel he should be really strongly plugging the issues and making strong statements. They say he's been flip-flopping. I have been seeing him on vacation, playing football and other things, but time is running down. I don't think he's being very forceful."

Democrats had hoped that their convention in Boston would introduce Kerry to voters and give them ample reasons to support him. But the survey suggests that those efforts did not succeed. A majority of those voting for Kerry -- 55 percent -- still say they are voting against Bush, not for Kerry. Barely four in 10 said their vote was more for Kerry than against Bush -- a percentage that has changed little since March.

"I'm more anti-Bush," said David Kolker, 37, of Creve Coeur, a suburb of St. Louis. "I really don't think Kerry has a chance -- he has not really taken a stance as far as defending himself against Bush."

In contrast, more than eight in 10 Bush voters say they are casting their vote for Bush and not mainly because of concerns over Kerry. And nine in 10 say they strongly support the president.

"I'm pro-Bush all the way," said Vicki DeScalfani, 57, of Boise, Idaho. But she does have reservations about Iraq. ". . . I think the war on Iraq was wrong. . . . I want to ask Bush what his thinking was."

A total of 1,202 randomly selected adults, including 952 self-described registered voters and 788 likely voters were interviewed by telephone Sept. 6-8. The margin of sampling error is plus or minus three percentage points for the results based on the sample of likely voters and slightly smaller for results based on the entire sample.

Senior polling analyst Christopher Muste contributed to this report.