What people need to understand about
www.electoral-vote.com is they do some of their own polling, but they also use many of the other state polls as they become available. Move your cursor over each state and it will tell you which group did the poll and from what dates. A poll can seem to switch quickly and drastically based upon which poll is being used to call that state. My impression on most of the major polling firms are:
Gallup - fairly reliable
Pew - not very reliable, they showed a similar lead to Gallups and didn't like the numbers, so they changed the questions and did a second wave of polling... surprise surprise the new poll shows a neck and neck race
Survey USA - relative new comer, they seem to be middle of the road in their projections
Rassmussen Group - very conservative in their polling methodology... they have been low-balling Bush's performance, and only recently started showing some seperation in the race with an approximate 4 1/2 point Bush lead. My rule of thumb with Rassmussen numbers is add 4% to overcome their overly cautious nature.
Harris - similar to Gallup, long reputation, pretty good track record.
Zogby - we used to use him extensively in NY, and at one time he was among the best. He is now a complete whore who will sell his polling results to the highest bidder... Do a search on Google using "Golisano and Zogby" and prepare to be blown away! He is also an Arab with a decidely anti-Bush bias. My rule of thumb is when Zogby polls on Bush add about 3-4% to overcome Zogby's bias.
A great site to see a lot of poll data is
www.realclearpolitics.com