Both Democrats trail Republican John McCain

Democrat Barack Obama's big national lead over Hillary Clinton has all but evaporated in the U.S. presidential race, and both Democrats trail Republican John McCain, according a Reuters/Zogby poll released on Wednesday.

The poll showed Obama had only a statistically insignificant lead of 47 percent to 44 percent over Clinton, down sharply from a 14 point edge he held over her in February when he was riding the tide of 10 straight victories.

Illinois Sen. Obama, who would be America's first black president, has been buffeted by attacks in recent weeks from New York Sen. Clinton over his fitness to serve as commander-in-chief and by a tempest over racially charged sermons given by his Chicago preacher.

The poll showed Arizona Sen. McCain, who has clinched the Republican presidential nomination, is benefiting from the lengthy campaign battle between Obama and Clinton, who are now battling to win Pennsylvania on April 22.

McCain leads 46 percent to 40 percent in a hypothetical matchup against Obama in the November presidential election, according to the poll.

That is a sharp turnaround from the Reuters/Zogby poll from last month, which showed in a head-to-head matchup that Obama would beat McCain 47 percent to 40 percent.

"The last couple of weeks have taken a toll on Obama and in a general election match-up, on both Democrats," said pollster John Zogby.

Matched up against Clinton, McCain leads 48 percent to 40 percent, narrower than his 50 to 38 percent advantage over her in February.

"It's not surprising to me that McCain's on top because there is disarray and confusion on the Democratic side," Zogby said