The exit polls were skewed. Kerry voters were younger, and more enthusiastic in their drive (usually Bush hatred rather than any special affinity for their guy.) They are not shy about mouthing off their beliefs. They would certainly be more willing to walk the minimal distance to the young-person-manned exit poll table setup than would the typical Republican.
To suggest that the treasonous John Kerry actually won is ludicrous.
More of a wonder is why he didn't lose by 15%. That has me scared for our republic.