WASHINGTON -- Although Democrats are tangled in a fractious primary contest, both Hillary Rodham Clinton and Barack Obama probably would win the White House against presumptive GOP nominee John McCain if the election were held now, according to a new Los Angeles Times/Bloomberg poll.

Arizona Sen. McCain remains competitive, but the poll identified one important vulnerability: Voters ranked him lowest among the three candidates on who could best handle the nation's economy -- by far the most pressing concern for the public irrespective of party, gender or income. Of the three main candidates, New York Sen. Clinton inspired the most confidence on the economy.

In a hypothetical matchup, the poll gave Illinois Sen. Obama 46% to McCain's 40%, with 9% undecided.

Clinton led McCain 47% to 38%, with 11% undecided. The nationwide poll, conducted May 1 through Thursday and released Friday, had a margin of sampling error of plus or minus 3 percentage points.

The results represent a shift from a Times/Bloomberg poll in February, when McCain led Clinton by 6 percentage points and Obama by 2, within the poll's margin of error.

"Although there is such infighting now between the two Democratic candidates, we are finding that both Democrats are beating McCain, and this could be attributed to the weakening of the economy," said Times Polling Director Susan Pinkus, who supervised the survey.

For example, among the 78% of voters who said they believe the economy has slid into a recession, 52% would vote for Obama, compared with 32% for McCain. A Clinton-McCain matchup showed nearly identical results.

The poll was based on telephone interviews with 2,208 adults nationwide -- 1,986 of them registered voters -- several days before and after Tuesday's primaries in Indiana and North Carolina, which Clinton and Obama split.

Those primary results were a disappointment for Clinton, who trails Obama in delegates and the popular vote and had hoped for a much stronger showing to swing momentum her way.

It now appears all but inevitable that Obama will be the Democratic nominee, though Clinton continues to campaign aggressively ahead of the final six primaries.

The poll offered fresh insights for Democrats weighing which candidate, Obama or Clinton, would have the best chance against McCain in the fall.

For example, among voters 65 and older, Clinton and McCain were essentially tied; but McCain led Obama 47% to 41%.

Among people ages 18 to 44, Obama led McCain 55% to 35%. Clinton led McCain 48% to 35%.

African Americans would vote overwhelmingly for Obama, the first black candidate with a realistic chance of becoming president. In the poll, he carried 79% of African Americans, with 3% supporting McCain.

In a matchup with Clinton, McCain's share of the African American vote rose to 9%, roughly in line with the performance of past GOP presidential candidates. Clinton had 60% of the African American vote; 23% of respondents in this cornerstone Democratic constituency said they were undecided.

Among baby boomers -- the giant post-World War II generation that will begin to reach retirement age in the next president's term -- both Democrats edged out McCain: Clinton 47% to 39%, Obama 45% to 37%. Whoever is elected will face serious Medicare and Social Security shortfalls.

McCain remains competitive because of his showing among older voters and independents -- constituencies both parties are vying to win. McCain leads Clinton among independents and is essentially tied with Obama.

Beyond divisions of race, gender, politics or income, voters' dominant concern is the state of the nation's economy, the poll found.

Although recent government data showed that the economy continued grow from January through March, many experts believe it was running on fumes and may well be shrinking this quarter.

Fifty-six percent of voters said the economy should be the top priority for the presidential candidates to address. Thirty-four percent said the war in Iraq should be the top priority. Healthcare and illegal immigration were the only other issues to break double digits, with 11% apiece. (Respondents could choose two.)