Jim Geraghty at National Review Online makes a tongue-in-cheek prediction:
One month from now, the Palin pick has proven a bonanza for the McCain campaign. A large chunk of Hillary's 18 million voters have been won over. Conservatives are unified and energized, and the previously-undiscovered "Maxim magazine vote" is suddenly giving McCain large margins among young males.
Joe Biden will disappear from the campaign trail, and we will later learn it was to see a doctor. A previously-undiscovered, vaguely ominous health issue will be discovered, and Biden will sadly announce that he cannot continue as Obama's running mate. With a sudden need for a new one, Obama will turn... to Hillary Clinton.
Call it the Torricelli gambit.
This is a reference to incumbent New Jersey Democratic Senator Bob Torricelli who fell under an ethical cloud just before the election in 2002. With his poll numbers dropping off the chart he was pressured by the party to drop out of the race so Frank Lautenberg could be appointed to run in his place. Lautenberg won.
Maybe Geraghty's idea is not so tongue-in-cheek.
RLC