That poll showed Obama beating all the "major" GOP contenders-with McCain and Huckabee doing the least badly-and Thompson and Romney doing the worse.
According to the Zogby poll, the race would be tighter if Hillary Clinton were the nominee.
Now this data needs to be tempered with the electability data from Intrade.com
According to Intrade.com, Obama is slightly less likely to get the presidency if nominated (odds of 55.2% for Obama vs. 62% for Clinton). What is the difference? Well, I expect this is in what the Zogby poll left out :
What if the race were between Ron Paul and Barack Obama? In that case, we have two candidates who both have records of opposing the War in Iraq—and Paul was actually in Congress at the time so he has a clear record of voting against the war resolutions—over the objections of a president from his own party.
Now, the other thing that is interesting here: from an immigration angle: Paul is the only relative moderate on immigration running for the GOP nomination with a measurable chance of getting the nomination. Every other candidate either has a clear record supporting increased immigration or significant increases in guest worker visas—or depend on the support of people who push for immigration expansion.
I suspect the reason for Obama's limited electability is that when matched against a candidate with similar views on the Iraq war and who is also more sane on the issue of immigration, a lot of Obama's big advantages simply disappear—and this is something that markets show more clearly that polls of selective competitors.
The Ron Paul organization has enough money now that they could in fact commission some similar polls from Zogby or other similar organizations—I hope that they do and look forward to seeing those results.