Ever hear of exit polling? It's the same way they do on election night. Man, are you a crabcake.
If he is up 8% of early voters, you have to remember not every state allows it.
Of the states that allow early voting, Bush won them 51 to 47 in 2000 (in the final, total count).
What this means is that Bush is beating his 2000 numbers by 4%...but we don't know how he performed with just early voters in 2000. My guess is they were probably split 50/50 then.
All in all, good news.
What were you saying about exit polling?