Democratic nominee John F. Kerry has gained ground on President Bush since last week's presidential debate and narrowly trails Bush among likely voters in one of the most closely followed presidential campaigns in at least two decades, according to the latest Washington Post tracking poll.

Bush leads Kerry 49 percent to 47 percent among those most likely to go to the polls. Independent Ralph Nader continues to barely register nationally, receiving 1 percent of the vote while 3 percent of voters remain undecided. Among all registered voters, Bush holds a three percentage-point lead.

The poll also found that most Americans believe they have not gained ground economically since Bush took office. Thirty percent said they are now better off financially than they were in 2001 while an equal share say they were not as well off. Forty percent said they have stayed about the same. Likely voters also divide over which candidate would best handle the issue of taxes but by a small margin think Kerry would do a better job handling the federal budget deficit.

The economy, budget deficit and taxes are expected to be some of the topics raised Friday as the two candidates square off in the second presidential debate, a confrontation that has taken on new urgency for Bush in recent days.

The daily tracking survey suggests that the race has tightened since last week as the proportion of Democrats and Democratic-leaning independents enthusiastic about their candidate surged following Kerry's strong showing in Thursday's presidential debate.

The latest results are based on interviews conducted Sunday through Tuesday night, although the majority of Tuesday's interviews were completed before the vice presidential debate. A total of 1,481 registered voters, including 1,155 likely voters, were interviewed. Margin of sampling error for both samples is plus or minus three percentage points.

Bush's current two-point advantage among likely voters is well within the survey's margin of sampling error, marking the closest the race has been since late August when the two candidates were tied immediately before the Republican convention in New York. Since that time, Bush has led by as many as nine points, the lead he held one month ago after the GOP convention in New York.

The survey suggests that a small but persistent number of likely voters could change their minds in the upcoming four weeks of the campaign. One in eight current Bush and Kerry supporters say there's a chance they could switch allegiances before election day, a proportion that hasn't changed significantly in weeks.

Interest in the presidential campaign remains unusually intense. Fully half of all registered voters say they're following the race "very closely." Four years ago, fewer than a third -- 30 percent -- of all voters were paying similar attention to the campaign in early October even though no incumbent was running and surveys suggested a close contest. In fact, while the polling record is incomplete, the current campaign has generated more interest than any race since at least 1980.

The campaign promises to get even more interesting following Tuesday's vice presidential debate. Instant polls conducted Tuesday night suggest that Vice President Cheney narrowly won among all debate-watchers, although some surveys suggested that Sen. John Edwards did slightly better among undecided voters and those lightly committed to their current choice.