Democrat Barack Obama holds a 4-point lead over Republican John McCain in the US presidential race, according to a Reuters/C-SPAN/Zogby poll released on Saturday.
Obama leads McCain by 48 to 44 per cent among likely US voters in the four-day tracking poll, which has a margin of error of 2.9 points.
Pollster John Zogby said that while Obama's overall lead had remained relatively stable between 2 and 6 points in the 12 days since the poll started, the latest figures showed a bump for McCain following Wednesday's final presidential debate.
"Today was the first full sample post-debate and there's a clear indication that McCain is moving up," Zogby said.
He added that McCain's support among Republican voters appeared to be consolidating.
McCain was backed by 91 per cent of Republicans in the poll, while Obama drew support from just 88 per cent of Democrats. But Obama still enjoyed a 16-point advantage among independent voters, which many analysts expect to be a deciding factor in the Nov 4 election.
"If (McCain) maintains his edge with Republicans, he stays competitive. But he's going to have to increase his share of independents," Zogby said.
Obama, 47, has seen his lead widen in recent weeks amid the global financial crisis, with voters consistently giving him higher marks on economic management.
The 72-year-old McCain now leads in only one age group -- those aged 35-49 -- while Obama has the edge in virtually all others including the most elderly voters.
"That has got to be the impact of the economy on those who are nearing retirement or in retirement," Zogby said.
But while Obama still has an 7-point lead among women voters who could be an important factor in the election, this advantage has dropped by 4 points over the course of the last two tracking polls, Zogby said.
"And I can tell you what that means: Republican women going back to McCain," he said.
Independent Ralph Nader drew 2 per cent support in the poll, conducted Saturday through Tuesday, while Libertarian Bob Barr registered 1 per cent, although support for both appeared to be slipping fractionally as the election draws closer.
The rolling tracking poll surveyed 1,210 likely voters in the presidential election. In a tracking poll, the most recent day's results are added while the oldest day's results are dropped in an effort to track changing momentum.
The US president is determined not by the most votes nationally but by a majority of the Electoral College, which has 538 members allotted to all 50 states and the District of Columbia in proportion to their representation in Congress.