McCain still has time and hopes that the attacks will swing the momentum in several important swing states.
In Pennsylvania, Obama leads 48 percent to 38 percent; and in Florida, 48 percent to 46 percent, according to latest battleground polls monitored by ABC News.
As a new ABC News/Washington Post poll indicates, Obama has taken a commanding lead in Ohio, where days ago the two were virtually tied, in large part because of the area's economic difficulties.
Obama now leads McCain, 51 percent to 45 percent, among likely voters in Ohio, according to the poll. Though 18 percent of the respondents said they had not yet made up their minds for sure, Obama had the advantage of the sheer energy of his backers. Fifty-eight percent of his Ohio supporters are "very enthusiastic" about his candidacy, compared with 30 percent of McCain's.