A new poll suggests Barack Obama has a seven-point lead over John McCain in the race to the White House, but nearly 10 per cent of voters have yet to make up their minds.

The Zogby poll, released Wednesday, also suggests independent candidate Ralph Nader and Libertarian candidate Bob Barr would draw votes away from McCain, thereby extending Obama's lead even further.

When respondents were asked who they would vote for if only given the choice between Obama, McCain and "someone else," most said they would support the Democratic candidate:

  • Obama: 47 per cent
  • McCain: 40.3 per cent
  • Other: 2.9 per cent
  • Undecided: 9.8 per cent

However, when the same question was repeated with the names of Nader and Barr added, McCain lost support.

  • Obama: 46.3 per cent
  • McCain: 36.3 per cent
  • Nader: 3.3 per cent
  • Barr: 3.4 per cent
  • Other: 1.1 per cent
  • Undecided: 9.6 per cent

"The key thing here, in this poll anyway, is that Obama is doing better among fellow Democrats than McCain is with fellow Republicans," pollster John Zogby told CTV's Canada AM on Wednesday.

The poll also suggests McCain faces an uphill battle in the election because of voter dissatisfaction with the current Republican government. More than two thirds of voters -- 72.9 per cent -- said the U.S. was on the "wrong track."

Also, only 12 per cent of respondents felt that McCain's main campaign issue -- the Iraq war -- would be a deciding factor in who to vote for. The economy was by far the top issue, with 47.1 per cent saying it would determine who got their support.

The poll suggested that 43.6 per cent of voters felt that Obama was better able to handle economic issues, compared to 40.3 per cent for McCain.

Which running mate?

Both parties' presumptive nominees have yet to announce a possible running mate. But the poll suggested their choice will have a strong impact -- both negative and positive -- on how many votes they can expect.

The poll suggests Hillary Clinton, who fought a gruelling campaign against Obama to represent the Democrats, would be a divisive figure in the race to the White House.

When respondents were asked if they would vote for Obama if Clinton were his running mate, less than half said it would make no difference:

  • Much more likely: 18.9 per cent
  • Somewhat more likely: 10.8 per cent
  • Somewhat less likely: 5.3 per cent
  • Much less likely: 19.8 per cent
  • No difference: 43.9 per cent

Of the possible running mates the Zogby poll included, Gen. Colin Powell, President Bush's former secretary of state, seemed to attract the most support for Obama:

  • Much more likely: 23.1 per cent
  • Somewhat more likely: 18.5 per cent
  • Somewhat less likely: 3.1 per cent
  • Much less likely: 6.4 per cent
  • No difference: 47.4 per cent

Zogby called Powell a "larger than life centrist figure" who appears to present Obama voters with a "suitable backup."

The two candidates who could shift McCain's fortunes are former nomination candidates Mitt Romney and Mick Huckabee, the poll suggested. Results showed Huckabee would be the most divisive among those deciding whether to vote for McCain's ticket:

  • Much more likely: 11.2 per cent
  • Somewhat more likely: 16 per cent
  • Somewhat less likely: 2.9 per cent
  • Much less likely: 9.8 per cent
  • No difference: 58.1 per cent

Romney's possible selection as McCain's running mate appeared to give the ticket the most added support:

  • Much more likely: 13.9 per cent
  • Somewhat more likely: 11.7 per cent
  • Somewhat less likely: 3.5 per cent
  • Much less likely: 7 per cent
  • No difference: 61.6 per cent

But Zogby appeared cautious about reading too much into the numbers regarding Huckabee and Romney.

"You can argue that these are two better known names," he said.