From MyDD:
Democratic self-identifiers come in at around 1/3 of the electorate, with Republican self-identifiers just slightly below that. If we can assume that those who identify as none of the three choices split proportionally to the rest of the population (not a stretch by any means), Harris would come out to 39% DNC, 33% RNC and 28% indy. For NAES, the numbers would be 38% DNC, 36% RNC, and 26% indy. Considering this, much of the bounce from the Newsweek poll is generated by poorly weighted Party ID numbers.
Party ID Bush Kerry Und/Oth
Republican 38% 94 4 2
Democrat 31% 14 82 4
Independent 31% 45 40 15
Total 100% 52 41 7
However, if the sample was properly weighted, here are what the results would look like:
Party ID Bush Kerry Und/Oth
Republican 35% 94 4 2
Democrat 38% 14 82 4
Independent 27% 45 40 15
Total 100% 50 43 6
(snip)
In reality, in the Newsweek poll Kerry is only down by seven in a three way trial heat, and thus is probably only down by 5 or 6 in a two way trial heat.
Link:
http://www.mydd.com/