"This is a threat."
A threat that would serve what purpose?
To make sure he gets a seat at the table? To make sure that his green ideas are part of the platform?
None of these would satisfy Al. They would just be promises that don't have to be kept by Queen Hillary.
I believe you are right that Al knows what the consequences would be of him running as a 3rd party candidate. I just really wonder, though, if he would tell himself, as the all-seeing Goracle, that his message of certain doom for the planet is so important that he has to run anyway.
He has turned into a religious nutcase over Global Warming, and those types don't necessarily act rationally.
Al Gore doesn't believe in man-made catastrophic global-warming any more than L. Ron Hubbard believed in Xenu, thetans or soul-catchers. His "green ideas" are just his tools. Like a hammer. Or a sickle. Don't make the mistake of thinking he actually believes this stuff. He's a deranged narcissist, but he's not an idiot.
The third-party threat is a threat of mutually assured destruction directed at the Clintons. I believe it means he's going to enter the race as a Democrat. And if he loses the race to what he perceives to be "smear tactics" or unfair hits from the Clinton-press (like the New York Times' piece last week), he'll run as a Green -- like a sort of Ralph Nader-meets-Godzilla -- and take the entire Democrat party down with him.