Barack Obama maintained a lead over John McCain in the White House race in three national polls published on Tuesday, but voters still trust McCain more to lead the country in the face of a major crisis as president.
Less than four months before the November 4 presidential election, Democrat Obama held a lead of six to eight points among registered voters in the three surveys -- 50-42 percent in the Washington Post/ABC News poll, 44-37 percent in the Quinnipiac poll; and 45-39 percent in the CBS/New York Times results.
The polls showed Obama's lead over his Republican rival anchored on a firm support base of women voters, young people and the African-American community.
But they showed that voters of the white ethnic majority prefer McCain over the African-American Obama, and that a rise in undecided voters leaves the presidential race fluid.
"Senator Barack Obama's national lead is solid - but it's not monolithic," said Maurice Carroll, director of the Quinnipiac University Polling Institute.
With the two rivals sharply divided over US national security policy, in the Post/ABC survey 50 percent of voters notably said they trusted Arizona Senator McCain to lead better in a crisis, against 41 percent for Obama.
That sentiment was echoed in the CBS News/New York Times poll. While those surveyed gave Obama a six-point lead overall over McCain, 82 percent felt McCain, a former navy pilot who was held prisoner of war in Vietnam, would be an effective commander-in-chief, while only 62 percent felt Obama would be effective.
Nevertheless, the polls showed voters by a broad spread consider the country's economic woes the most important issue in the presidential campaign, and trust Obama more to handle the issue, by a large 53-39 percent margin, according to Quinnipiac.
And the CBS/Times Poll showed that voters trust Obama more to improve the US image in the world.
But the same poll shows a rise in undecided voters. Asked how they would vote if the election was held now, 12 percent called themselves undecided, compared to just six percent in June.
And asked if their mind was "made up" at this point, 28 percent said no.
The Quinnipiac data meanwhile showed the number of undecided voters had risen to 14 percent from eight percent two months earlier.
Copyright © 2008 Agence France Presse. All rights reserved.