hmmm y'know this topic is like an onion
lets peel another layer and see if it makes anyone cry
Independent polling as well as research by the Green party itself showed that in excess of 50% of Nader voters in 2000 would not have voted AT ALL if there was no Green party candidate.
In addition they found that another 15-20% of Nader voters would otherwise have voted for the Libertarian candidate Harry Browne or (esp. if Browne were not there) even for BUSH. Yes yes I know that's ridiculous and all; I wouldnt have believed it myself if I didnt know a couple of Libertarians who voted for Nader because of his extreme social liberalism/libertarianism especially on Marijuana legalization etc. With Nader out of the equation, they disliked both major parties social stances almost equally but would have voted for Bush on economic issues (as the lesser of two evils)
The rest would have considered voting for Gore or maybe the nominee of another left/liberal party like Natural Law if that party(s) made themselves known as such.
Now with all the (non-voting) or (voting for another third party) folks taken out of the equation and taking away (subtracting) the votes (say 5% of total) that might have actually have gone to Bush; Gore is left with a NET gain of only 15-20% of Nader voters, tops.
Now I regrettably cannot complete my argument because I have no figures on how many Reform/Libertarian voters would not have voted and how many would have voted for Bush if their candidates did not run.
Given what I know of these parties and their voters I believe the Bush Net gain would have been enough to overcome the 15-20% net Gore would have got from Nader dropping out.
Thus I surmise that the presence of the Green, Reform and Libertarian third party candidates in the 2000 race ended up hurting Bush a lot more than Gore.
Will look forward to reading the enraged rebuttals.