Then either John McCain or Colin Powell will be asked to come on the ticket and save the party. If we get the rumor out on the internet, they won't be able to do their calculated move without repercussions. This is the point at which I'd normally say, if I could, that I have spoken to Bush campaign officials and they deny all this. Unfortunately, they won't return my phone calls. Not that it really matters.
Conspiracy theories are naturally immune to debunking.
The answer, as any frequent visitor to this site knows, is almost never. Opinion polls give him an approval rating comparable to Democratic vice-presidential candidate Joe Lieberman. He's also a phenomenal fundraiser. More to the point, Cheney was known to have a history of heart disease when he was nominated. It wouldn't reflect well on G.W. Bush's decision-making abilities if Cheney ultimately bowed out due to illness.