I can't help but wonder who was the more exasperating VP to his President... Dan "Potato" Quayle, or Joe "Two Shots" Biden.
I can't think of a single president or candidate, with the exception of Reagan, that picked a sober VP.
Seriously the VP's job is to act as a campaigner for the presidential candidate. In the past couple of years we have moved to a permanent political campaign. (something the GOP doesn't understand in the least).
Biden isn't talking policy, he is politicking, even though neither he nor Obama will run again, he is campaigning. Their entire strategy is to win congress in 2014. Once you look at the actions of the administration from that point of view, everything makes sense.