John McCain has opened up a six point lead over Barack Obama, and holds an eight point lead over Hillary Clinton in a new Reuters/Zogby Poll out today.

46% John McCain
40% Barack Obama

48% John McCain
40% Hillary Clinton

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