>The problem that is trivially easy to solve (unless some left-wing
>celebrity wants to be a real asshole) is to prevent the splitting of
>the left-of-center vote by having more than one left-of-center
>candidate campaigning.
You make it sound easy, but is it? The Devil is in the detail and the tricky question is, are the Democrats in the US a "left-of-center" party? It all depends on where the "centre" is.
The civilised world has solved this problem with preferential voting. That isn't what you mean of course, you mean that the easy solution is blackmail every left of centre voter into voting for the most right wing of the left of centre candidates.
In the US this seems to have the effect of allowing the right wing candidates to move further to the right at warp speed (trying to keep some distance between them and the right wing of the left wing.)
So the "centre" is constantly moving, rightward, because the right wing of the left of centre candidates always tries to narrow the gap between them and the left wing of the right wing candidates.
This causes some confusion as to exactly where the "centre" is. If you don't know that, then its really hard to tell who is a "left of centre" candidate. Obviously you can't just vote for the candidate whose policies you like, that might be interpreted as "taking of an "oppositional stance" rather than an attempt to make the world a better place".
Here in Tasmania, where preferential voting has been around for over 100 years, the Greens can expect to get around 15% of the Primary vote and their preferences will decide the outcome in at least 3 of the 5 federal electorates in next years election. So the new Labor party leader has quickly accepted an invitation from the Greens leader Bob Brown to be taken on a tour of several forest areas threatened by clear felling. The votes of those who vote Green actually count towards the final result you see.
In the US they can also count, if only by not being counted. The Green voters can allow themselves to be blackmailed into voting for one of the right-wing candidates, or they choose to turn the tables. Voting for their candidate of their choice and the policies of their choice forces the right wing parties to confront the issue of electoral reform. Either bring the US electoral system at least into the 20th century, or face the prospect of losing sufficient votes to lose them the election.
On the other hand, Mr DeLong's suggestion - that Green voters vote for someone else, definitely means their votes wouldn't count. At least their votes wouldn't count the way they would prefer them to be counted.
Its trivially easy.
Bill Bartlett Bracknell Tas