Republican presidential candidate John McCain speaks at a town hall meeting in Rocky River, Ohio February 25, 2008. (Xinhua/Reuters, File Photo)

Presumptive US Republican presidential nominee John McCain poses a stiff challenge to either of his potential Democratic opponents in the general election, a new poll has shown.

The Los Angeles Times/Bloomberg survey, which came out Wednesday, underscores the difficulties ahead for Democrats as they hope to retake the White House during a time of war, with voters giving McCain far higher marks when it comes to experience, fighting terrorism and dealing with the situation in Iraq.

Both Democratic candidates Sen. Barack Obama of Illinois and Sen. Hillary Rodham Clinton of New York have made ending the Iraq war a centerpiece of their campaigns.

However, even though a clear majority of those polled said the war was not worth waging, about half of registered voters said McCain – a Vietnam vet who has supported the Bush administration's military strategy – was better able to deal with Iraq.

In head-to-head contests, the poll found, McCain leads Clinton by 6 percentage points (46 percent to 40 percent) and Obama by 2 points (44 percent to 42 percent).

McCain is viewed favorably by 61 percent of all registered voters, including a plurality of Democrats.

In the Democratic race, the survey showed, Obama's support has increased across all of the party's key constituencies.

(Xinhua News Agency February 28, 2008)