I read on another BB site that they have a margin of error of 3%. I can't vouch for that figure though as it was out up by another poster and I don't recall if (s)he had a source backing it up.
Oboe, I'm sorry to hear that. I wish people on both sides would take the effort to educate themselves with the real facts and make their choices based on that. I respect a Republican who knows their facts and votes Republican based on them a heck of a lot more than I do a Democrat who doesn't and votes based on rumors and propaganda, even though I agree with the Democrat's vote. Whatever your choice, make it an informed choice.
Here's a real fact: Bill Clinton's surplus was only a surplus if you count raiding the Social Security taxes (a standard tactic that Administrations of both partys do and one of the biggest reasons Social Security is in so much trouble) that were coming in. The best he, and the Republican Congress, did in real terms was to massively shrink the deficit.