You can see Battleground's record from 1992-2004 here.
Gallup's state polls were pitiful this year, and hopefully they drop that idea in the future.
Gallup could have easily gotten the national numbers on the button if they didn't allocate the undecideds in such a nonsensical manner. Their final data gave Bush a 49-47% lead over Kerry, but then the proceeded to allocate 90% of the undecideds to the Kerry column, this being the only way for them not to have to call the race either way.
Distributing it at a more reasonable 50% would have made their projection 51-49, but it was their own credibility.
In addition to being of dubious origin, the "undecided" supposition was based upon iffy premises, which anyone with an ounce of common sense would be able to see through.
My own personal opinion was that most of these "undecideds" were simply people who wanted to be given a reason-virtually any reason at all-to vote for President Bush, not the other way around.