"But my guess is that by 2008 there won't be a Democratic Party for either of them."
While I like your words and essay, I think you are being much too optimistic.
he Dems will not go away that easily. Remember Perot? 10 years later there's nothing left of his movement, one that reached 33% of the vote in some states. Why? Because both of the major parties co-opted his message. Neither party speaks with one voice and so neither can be eliminated by destroying one voice.
They may fall into a long and bad lull, like the GOP in CA and IL, but they won't go away, and their base bought by your's and my tax dollars isn't going to give up and go away easily either. Still, I hope you are more right than I.
That is the key sentence. I don't think that any of the many voices that make up the Democratic Party will be destroyed. The larger question is whether these factions can still work together and whether certain factions will walk away when the dangerously strident take control of the party.