When do you think the next time a third party will take a significant (at least 10%) number of votes, and what side of the spectrum will it draw from?
I think it will be 2016 and it will be the libertarians.
It might be. Many moderately Libertarian Specter Republicans may leave the party, instead of being RINOs.
I think the only successful third party we could have is a breakaway centrist party made up of the Specter/McCain/Snow wing of the Republican party and the Liberman/Breaux wing of the Democratic party. I see a party like this able to poll in the mid 20's in the popular vote and win some states. Only problem is that the moderates will probably never break away from their parties so its a pipe dream.