Obama's support increased to 54 per cent when Nader was not included as a candidate.
Support for the Republican party has plummeted after eight years of US wars in Iraq and Afghanistan, the poll found.
"People are switching to the Democratic camp because of the domestic and foreign policy mess the administration has created," James Zobgy of the Arab-American Institute, told Al Jazeera.
Arab-Americans make up more than one per cent of the total US population, but more than one-third of them live in Michigan, Florida, Ohio, Pennsylvania and Virginia - states that will be hotly contested in the election.
That could boost Obama's chances in key swing-states like Michigan that have large Arab-American populations.
Sixty-seven per cent of those surveyed said the economy was the most important issue to them, followed by the Iraq war and health care.
Arab-Americans, like the wider US population, were also critical of George Bush's presidency, with only 23 per cent saying he had done a good job in the White House.
The poll, conducted by polling firm Zogby International, was based on 501 interviews conducted earlier this month.