Why does democratic party reject new blood?

Kerry will win Iowa, that's a joke two weeks ago, but it seems very likely now.

Why does democratic party always make stupid decision. Dean has energized a lot of people, he's injected new blood to the party, he's brought more money to the party.

But the party chooses to reject the new blood instead of embracing it. The democratic party tried the old Washington insiders in 2002, what's the result? an ultimate failure. If this party chooses to go back to its old way, this is really a party with no hope, it's a party which will become a permannet minority for years to come.
I firmly believe this is not just about Dean, it's a battle for the life of democratic party. If Dean or Clark loses, the democratic party will become a party of old washington insiders, seniors, minorities.. in one word, a party of the past.

If only 10 - 20% sit it out, not only Bush's reelection is guaranteed, the democrats will lose congress as well.

If it were Kerry, I would say a lot of folks would just give up on this party.