When The Times and CBS News first asked the question, more voters said they believed Mr. Obama was not ready, 49 percent, than believed he was, 44 percent. Mr. McCain still holds an advantage on that front, with 64 percent saying they believe he is prepared for the presidency.

There was also fresh evidence that Mr. McCain’s attacks on Mr. Obama’s character and qualifications in commercials, mailings, speeches and automated telephone calls were, if anything, harming Mr. McCain. The percentage of people who view Mr. McCain unfavorably was at its highest level since The Times and CBS began asking the question in 1999. Forty-six percent said they held unfavorable views of him, with 39 percent saying they viewed him favorably. Mr. Obama was viewed favorably by 52 percent of those surveyed, and unfavorably by 31 percent.

Voters were almost evenly split over Mr. Obama’s ability to handle a crisis wisely: 49 percent said they were confident he could and 47 percent said they would be uneasy. Respondents showed less ease with Mr. McCain: 51 percent said they would be uneasy with his approach and 46 percent expressed confidence.

Mr. Obama fared better than Mr. McCain on economic matters: 65 percent said they were somewhat confident or very confident in Mr. Obama’s ability to handle the economy; 47 percent said the same thing about Mr. McCain.

In spite of Mr. McCain’s sustained attack on Mr. Obama’s proposal to raise income taxes on households and businesses that earn more than $250,000 a year, Mr. Obama’s plan received significant support in the new poll. When voters were asked whether they supported the tax increase to help provide health insurance for those who are not covered, 62 percent said it was a “good idea” and 33 percent said it was a “bad idea.”

Voters were evenly divided over Mr. McCain’s plan to make permanent Mr. Bush’s 2001 tax cuts.

In another area where Mr. McCain could take heart, the last two polls offered fresh evidence that his choice of Gov. Sarah Palin of Alaska as his running mate had helped to excite two traditional bases of support for Republican presidential candidates. White voters who say they attend church every week preferred Mr. McCain over Mr. Obama by 61 percent to 29 percent, and voters who live in the South preferred him over Mr. Obama by 51 percent to 40 percent.

But, over all, the percentage of those who view Ms. Palin unfavorably, 40 percent, was higher than those who view her favorably, 31 percent.