Oh, that part was obvious. They wanted to decapitate the GOP house leadership so they could push for Speaker-of-the-House Pelosi even harder since their campaign trail clarion after that would be that the "vacuum of leadership that needs to be filled"...by them. (gag..retch...puke)
Actually I was thinking that this was payback for what Newt and the GOP did to Jim Wright when he was the Dim leader of the house.