Among likely voters, Obama now leads GOP nominee John McCain 52 percent to 43 percent, results from the Washington Post/ABC News national poll released Tuesday indicate. Immediately after the Republican National Convention, the presidential race was a virtual dead heat, with McCain at 49 percent and Obama at 47 percent.

The poll indicates more voters thought Obama would handle the economy better than McCain, 53 percent to 39 percent. Fifty percent of respondents said the economy and jobs the single most important issue that will determine their vote, up from 37 percent two weeks ago.

The poll indicates McCain and Obama now are about even among white women, with Obama closing the overall gap among white voters to within 5 percentage points.

McCain's advantages on national security issues and battling terrorism also have eroded, pollsters said.

The survey conducted telephone interviews Friday through Monday with 1,082 adults. The margin of error is 3 percentage points.