how can they call states without

more than 50% counted???

percent of dems back Kerry. He can't possibly win WV with that kind of number.

Look at Ohio though, both men AND women favour Kerry!!

it's obviously not based on an actual count. technically, it IS possible that there's a HUGE surprise and all the uncounteds go the other way.

but what they do is look at the exit polls in known precincts and compare them to pre-election polls. if the exit polls are consistent with the pre-election polls, are lean even more heavily toward the favorite, then they can call the state.

more complicated, is that they look at the the leanings of the precincts. if a republican precinct is going for kerry, then it's REALLY unlikely that the democratic precincts will go for bush. you get the idea.

it's NOT 100%, of course, but they're willing to accept the "negligible" risk of having to reverse themselves.

after the 2000 debacle, though, they're probably a bit more cautious this time around.

Considering they just called Tennessee for Shrub when only the results for Republican EAST Tennessee are in. Nashville and Memphis still have an hour to vote in the CST, as far as I know. Unless they stop voting at 7 p.m. EST, but I don't think they do.
Memphis is HIGHLY Democratic and Nashville swings.