Gallup had Bush leading Gore by 13 points on October 26, 2000.
Which is indicative, in my view of reliability. W won, and the only reasons he lost the popular vote was because of the DUI dirty trick, "going positive" near the end, and taking the weekend off. Of course I doubt if any of these drawbacks/mistakes had not occurred, he would have won with anywhere near 13 points, but still.