Jim, you can just cancel this whole George/Colin and John/John notion.
On the Democratic side, a friend with Libertarian leanings remarked as to how he would lose any remaining shred of respect for McCain if he "crossed over". Not like that is a scientific survey of voter opinion, but the John/John scenario was the one that I thought was most far-fetched and I am ready to cash it in --- for any centrist pull it would exert it would likely create equal-but-opposed backlash.
On the George+Colin front, I am amazed by my own naivete. Sure, I had become convinced that Powell had become the Bush/Cheney lap dog -- and that is still true -- but I never had a true sense of the distrust between Shrub/Cheney and Powell. I was in Seattle's Bulldog News last week and spied a cover story "Misoverestimated. How a great general became a failure as a statesman" (or thereabouts) and grabbed it. The report (pretty full transcript
here ) makes it pretty clear how great the divide is between the Wolfowitz crowd and Powell, but also how compliant Powell is.
Anyhow, Powell (lacking any solid base political philosophy) seems willing to be marginalized and "go along" like a good soldier, but will never enjoy any degree of trust or support.
So, VP candidate? No.
The good news? Shrub (*yes* I hate him!) numbers are down. There is a good chance that Shrub will lose to career politico Kerry by a margin large enough that it will be hard to steal the election.