An on-line poll at qudsway.com, which is the official Islamic Jihad webpage, asks: Who is responsible for the Gaza massacre?
At the moment, out of 3000 votes, the tally is
The Zionist enemy - 20%
The Hamas government in Gaza - 13%
The Palestinian Authority in the West Bank - 45%
Arab silence - 21%
Islamic Jihad is a wildcard that people keep forgetting about. They are just as radical as Hamas but refused to take part in elections so we don't know how popular they are, but they are the second-largest military group in Gaza behinf Hamas itself. They have generally sided with Hamas and stayed out of the Hamas/Fatah battles in 2007. Hamas is coordinating their military plans with Islamic Jihad now, and clearly Hamas gave them carte blanche for terror training and rocket fire before this operation.
It appears that PIJ supporters hate Fatah nearly as much as Hamas does. In the supposed "best case" scenario (which is anything but), where Fatah takes over Gaza again, PIJ will not accept the PA's decisions on Israel. They need to be defeated as much as Hamas does, as do the other terror groups with rockets (PRC, PFLP and DFLP.) Otherwise, any of those will be poised to fill any vacuum that Hamas may leave behind, and perhaps half of Gazans can be expected to side with them.