This is a classic and often-used exercise in power.
McCain has something Bush badly needs. They both understand the rules.
McCain could simply roll over and give Bush what he wants, or he can negotiate it. What are they negotiating? McCains support, which would also influence the millions of supporters he has attracted. If he doesn't support Bush, those supporters disperse, and that would help Algore.
But Bush knows hardball equally as well. He may very well tell McCain no deal, and go out on his own to rebuild that independent base.
No one who plays for power gives it up without getting something back. That's rule number one. These rules go back to the beginning of tribes. No reason to think they would change now because we think we're "civilized". (That's what the gun banners think. We're civilized, so we don't need guns. Fact is we're only a few decades into the radical thought that power should change without the use of deadly force, out of how many millions as our species has evolved.)
Ok, if Bush agrees too quickly, he will be seen as weak, and admitting he can't build the independent coalition on his own. If McCain agrees too quickly, he is seen as betraying the trust of his supporters.
Expect this dance to continue for a while, until both can make a deal and save face.
By the way, McCain could be a devastating third party candidate, with a very good chance of winning (better than 30-40%). If he has no loyalty, that's the move he'll make.
I think it's a little harsh to think of the man as a coward. He may be a little mad, but cowardice is not a trait I would ascribe to him.
McCain is also fighting history and a strong set of personal demons. His grandfather and father were both Navy admirals, and warriors run in his lineage. He is clearly up to this fight with Bush. He also wants to be listed in his genealogy as an opponent worthy of respect.
We are watching, in my opinion, a power struggle among men born as warriors and anointed by history. This will be an all-time classic. This kind of stuff doesn't come along very often. Bush, Gore, and McCain come from generations of leaders and warriors. A true spectacle is unfolding!
The following story carries on this theme. Well worth the reading for fans of this kind of history!
Bush vs. Gore: final act in old play