I don't think the core problem with the GOP are the establishment Republicans. The Karl Rove types are corporate. They are willing to bend their policies to pull in votes (i.e., widen the tent). The Tea Party, on the other hand, is inflexible. They are camped on the far right and give no quarter. They are guarding the door to the GOP tent so I don't see how it expands.
Sorry, I meant for this post to go with DamainAllen's thread on the GOP. Must have hit the new thread button instead of reply.