Nader's Influence

It's fairly accepted conventional wisdom that Nader's presence in the 2000 presidential election was counterproductive and helped Bush win--his margin of victory was larger than the difference between Bush and Gore in several states, and Nader voters disproportionately favored Gore to Bush. However, this premise is by no means universally conceded, as some argue that Nader voters otherwise would have stayed home, or might have felt it was worth it to send the Democratic Party a message to take their issues more seriously. Nader's effects on the 2004 race, therefore, are not immediately obvious. Some arguments:

*Nader will help Republicans, as many who would have voted for the Democratic nominee will vote for Nader.
*Counterargument: Many disgruntled Democrats will use the 2000 experience to justify avoiding supporting Nader.
*Counterargument 2: Such voters would have stayed home anyway, and thus will not significantly affect the race.
*Counterargument 3: Voters energized by Nader's candidacy who would otherwise have stayed home will probably vote disproportionately for Democrats in the down-ballot races, helping Democrats more than Republicans in Congressional and state races.

*Nader will help Republicans, as his attacks on the Democratic nominee from the left will keep the Dem from moving as far to the middle as he needs to to attract swing voters.
*Counterargument: Or it could be that the issues of the Left will get more press coverage, and the additional attacks on President Bush will hurt him more than the posited electoral help.

*Nader's candidacy might "[invigorate] efforts to improve ballot access for third parties." Some would consider this a good thing.
*Counterargument: Some consider it a bad thing.
*Counterargument II: Between the California recall circus and disgruntled Democrats afraid Nader will throw the race to Bush again, many might work make it harder to get a third party on the ballot (which may be either a good or bad thing, depending).

*Nader's candidacy might elevate the level of political discourse in America, as issues and ideas which otherwise might not have been addressed will likely be considered.
*Counterargument: Or the horse race 'who will it help/hurt' coverage might continue to drown out issue coverage.

The Nader campaign's discussion of ballot access requirements in each state is here, and makes interesting skimming (275 signatures in TN versus 18,000 in NM?). I wonder to what degree Republicans convinced that Nader's entry helps them more than it hurts would find it productive to help in gathering signatures.