The poll of about 1,000 respondents on Friday and on Saturday showed President Bush garnering 50 percent to 47 percent for the new Democratic nominee, Sen. John Kerry; Bush trailed Kerry among likely voters earlier in July, 47 percent to 49 percent. Independent candidate Ralph Nader had 2 percent.

Among registered voters, Kerry received 50 percent to 47 percent for Bush. That compared with 49 percent for Kerry and 45 percent for Bush earlier in the month.

The CNN/USA Today Gallup poll had a 4 percent margin of error.

A Newsweek poll released on Saturday said Kerry gained a four-point boost in the polls from the Democratic National Convention held last week in Boston.

In the poll conducted on Thursday and on Friday, Kerry received 49 percent of the vote to Bush's 42 percent and 3 percent for independent candidate Ralph Nader. In early July, Kerry led Bush 47 percent to 44 percent, with Nader at 3 percent.

Kerry had been hoping for a measurable surge in public approval, known as "bounce," which sometimes has given nominees a double-digit boost in the polls following their four days in the spotlight. Democrats this year have said the closely divided electorate and relatively small number of undecided voters made a big bounce unlikely.

Kerry said he wasn't paying attention.

Appearing on "Fox News Sunday" with his running mate, Sen. John Edwards, he said he remembered the polls last year that showed his presidential bid staggering.

"Polls are not what's important. What's important is what we're going to do for America," Kerry said.

"I don't read polls. I really don't. They are going to go up and down. They're going to change," he added.