State polls lag behind national polls. The reason appears to be because any trend first hits non-swing states, which usually aren't polled very often.
For example, if a Republican starts to surge, the first place it happens is in states where he's already strong and there's a natural predisposition among the electorate to support him. It takes a few days longer for the issue that caused that surge to take hold of voters in swing states, who are more divided and have less tendency to sway to one party than the voters in more partisan states.
So if some issue, event, or gaffe causes the GOP candidate to start rising in the polls, the first places it hits will be GOP landslide states like Alabama or Kansas. That will cause the national numbers to rise, but since those states are rarely polled (since they aren't competitive) the state polls seem to show no movement. No one much notices if Bush's poll lead in Texas rises from 59-36 to 64-32, but a rise like that in several hardcore Bush states can affect the national numbers.
A few days later, the polls will start to move in the battleground states, when the issue, event, or whatever that caused the surge to start spreads to less partisan states where it takes longer for the issue to get a reaction.
That's one theory, anyway!
So stay tuned. Bush should look better in the battleground states soon.