Obama leads McCain by 6 points

WASHINGTON (Reuters) - Democrat Barack Obama’s lead over Republican rival John McCain firmed marginally to 6 points with support for both candidates steady before Tuesday’s U.S. presidential election, according to a Reuters/C-SPAN/Zogby poll released on Sunday.

Obama leads McCain by 50 percent to 44 percent among likely voters in the three-day national tracking poll, up from a 5-point advantage on Saturday. The telephone poll has a margin of error of 2.9 percentage points.

“There are two full days to go before Election Day and obviously anything can happen, but it is hard to see where McCain goes from here,” pollster John Zogby said.

He said the polling data over the weekend showed that both candidates appeared to be consolidating support among their core supporters -- women and independents for Obama, older voters and conservatives for McCain.

National opinion polls all give the lead to Obama, who also appears to be outflanking McCain in a number of the battleground states that will end up deciding the election.

McCain spent Saturday campaigning in Virginia and Pennsylvania -- states that electoral strategists regard as crucial to his hopes for victory -- while Obama pushed for an advantage in three states that went for President George W. Bush in 2004: Nevada, Colorado and Missouri.

The poll showed Obama well ahead among voters who had already participated in early balloting, leading McCain in this group by 56 percent to 39 percent.

Women and independent voters, groups that are expected to play an important role in this election, continue to back Obama although his margin is not as wide as it was late last month.

Obama enjoys an 8-point lead among women voters and a 10-point lead among independents.

McCain continues to hold a strong lead among white voters, 54 percent to 40 percent, and among voters who identify themselves as members of the “investor class,” who support him by a 9-point margin.

Obama, who would be the first black U.S. president, wins 93 percent support among black voters and 65 percent among Hispanics.

Independent Ralph Nader received 2 percent in the national survey, and Libertarian Bob Barr was at 1 percent. About 2 percent of voters remain undecided.

The rolling tracking poll, taken Wednesday through Friday, surveyed 1,201 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 to monitor changing momentum.

The U.S. presidency is determined by which candidate wins the Electoral College, which has 538 members apportioned by population in each state and the District of Columbia. Electoral votes are allotted on a winner-take-all basis in all but two states, which divide them by congressional district.