How about Dick Cheney?
Seems obvious to me.
Just before his term expires Bush pardons Cheney.
Then Bush resigns and Cheney pardons Bush.
Cheney probably also pardons a host of others including Rumsfeld, Libby, Rice, . . .
but wait, there's more!
My other theory is that just prior to the 2008 election the current administration will create a major terrorist incident in the U.S. and use this as a pretext to cancel the election and impose martial law. Then they will continue on, after all while a president may not be elected to more than two terms, there is I suppose nothing to stop him from extending his second term indefinately.
Nothing these people, Republicans that is, would do could possibly surprise me at this point. Of course there is nothing they wouldn't do.