[Steven Lyle Jordan]

I'm pretty sure that, if something happened to Obama at this point, Biden as his running mate would be given the President's job. However, if Biden couldn't do that, the job would possibly go to the next in line of succession-elect, which would be the new Speaker of the House of Representatives.

The Speaker of the House is elected by the members of the House, at the beginning of a new session (administration). That would mean the House, and not a public vote, would be selecting the next President, something that body has never done before, and would probably represent a s**tstorm in action.

If the House refused to take on that responsibility, we'd be writing new laws to figure out how to handle it, and all bets are off. (Edit: I say this before reading Daffy's comment, so maybe the 12th Amendment has got that covered.)