1. He really is that stupid.
2. Bill or Hillary convinced him to give that speech to kill him off politically. It flies in the face of current polls showing support for Bush, hurts other Democrats (as Gore is still seen as one of the party’s spokesmen) and it makes Gore an untouchable if the Bush Iraq strategy is successful. Neither Bill nor Hillary cares about the short term interest of the party if it clears the way for Hillary.
3. He intentionally goes hard left to grab headlines and the left wing of the party, gambling that the Bush plan runs amok, so that Gore eventually looks like a prophetic genius. (Sick)
I tend to favor a combination of one and two. As to his speech and hair, he's probably drinking Rogaine and inhaling Sterno.
This is the very best explanation I've seen so far!
ML/NJ