Obama lead on McCain slips to 9 points

WASHINGTON (Reuters) - Democrat Barack Obama's lead over Republican rival John McCain fell slightly to 9 points, according to a Reuters/C-SPAN/Zogby poll released Saturday, the second consecutive day the race has narrowed.

Obama leads McCain by 51 percent to 42 percent in the rolling three-day tracking poll, which has a margin of error of 2.9 points. Obama led by 10 points Friday and 12 points on Thursday.

Pollster John Zogby said McCain, who had seen his Democratic rival stake out a widening lead as economic issues dominated the campaign, appeared to be winning some converts with his own economic message.

"He scores points when he differentiates himself on the economy and when he lays off the negative. Negative campaigning is not working for anyone this year," Zogby said.

"What's important here is that this race is not over."

Obama, 47, has led many national opinion surveys in recent days as well as in polls in important battleground states where the November 4 election will be likely be decided.

But Zogby said the 72-year-old McCain over the past two days had been able to cut into the Illinois senator's main base of support among women and independent voters, a shift that coincided with his campaign's move to highlight differences between the two candidates' economic policies.

Women, who backed Obama by 20 points Friday, now give him a 16-point lead, and his lead among independents had fallen to 16 points from 26 Friday.

Zogby said that while the poll showed only 3 percent of voters remained totally undecided in the race, that number grew to about 16 percent if one included voters who were only leaning toward or moderately inclined to support a particular candidate.

"That means that more people have not completely made up their minds," Zogby said.

McCain's support was strongest among white voters, who backed the Arizona senator by 49 percent to 43 percent. Obama, who would be the first black president, won 92 percent support among black voters and 70 percent among Hispanics.

Independent Ralph Nader and Libertarian Bob Barr held relatively steady at 2 percent and 1 percent respectively.

The rolling tracking poll surveyed 1,203 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. president is determined by who 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.

(Reporting by Andrew Quinn; Editing by Peter Cooney)