A USA Today/Gallup Poll released Monday showed a similar result, 51 percent for Obama to 39 percent for Clinton.

The poll shows that Obama's coalition – originally derided by critics as confined to upper-income reformers, young people and blacks – has broadened significantly.

In December, for example, he had the support of 26 percent of the male Democratic primary voters; in the latest poll, that had climbed to 67 percent.

But there are signs of vulnerability for Obama, too.

While he has a strong edge among Democratic voters for his ability to unite and inspire the country, Clinton is still viewed by more Democrats as being prepared for the job of president.

And while he has made progress among women, he still faces a striking gender gap.

Obama is backed by two-thirds of the Democratic men and 45 percent of the women, who are equally divided in their support between the two candidates.

White women remain a Clinton stronghold.

When all voters are asked to look ahead to the general election, McCain is more likely to be seen as prepared for the presidency, able to handle an international crisis and equipped to serve as commander in chief than either of the Democratic candidates.

(Xinhua News Agency February 27, 2008)