Obama holds four-point lead on McCain

By John Whitesides, Political Correspondent

WASHINGTON (Reuters) - Democrat Barack Obama has a four-point national lead over Republican John McCain as they head into the final week of the U.S. presidential campaign, according to a Reuters/C-SPAN/Zogby poll released on Tuesday.

Obama leads McCain by 49 percent to 45 percent among likely voters in the three-day national tracking poll, a slight dip from his five-point advantage on Monday. The telephone poll has a margin of error of 2.9 percentage points.

McCain solidified his support among white and male voters but Obama retained double-digit leads among women and independent voters -- two key swing blocs in the November 4 election.

Obama had a strong single day of polling on Monday, pollster John Zogby said, and still holds a significant edge among Hispanics and Catholics, two groups who gave a boost to Republican President George W. Bush's re-election win in 2004.

"With seven days to go in this race, McCain is still not where he needs to be with some key groups and he is running out of time," Zogby said.

McCain, a veteran Arizona senator, has sliced Obama's 12-point advantage by more than half in the last five days but he has not been able to break through the 45 percent support mark.

When the national tracking poll debuted on October 6, Obama led by three points, 48 percent to 45 percent. In the ensuing three weeks, McCain's support has not been higher than 45 percent and Obama's support has not been lower than 48 percent.

MCCAIN TRIES TO GAIN