I know someone that has worked for Gallup for years... and she does not trust them. Take it for what you will.
LLS
Each pollster has to be eveluated based on their model. Gallup is ok, if you want to get a fast snapshot of the race.
Also, all polls I looked at show that McCain’s lead among white voters is down to 13-16% range. This is definitely not enough, a simple arithmetic shows he needs to be at least 19% ahead among whites to even make it close.