Zardari knows that if he becomes PM, he becomes a target. The guy has just burried his wife, who was shot dead or blasted or just died of ducking .. whatever be the reason, who the fk cares.
So, now Zardari is sh1t scared .... he would rather see Shariff dead ... why not? and since he has control of MPs or whatever they call them b1tches in pakistan, he is the king maker and will further ambitions of making more money via corruption in govt.