That is the best political move by Pres Parvez M. By inviting Shahbaz he is ensuring these guys do not crib about rigging the polls post elections. Shahbaz would become part of rigging then. If he refuses he would loose an opportunity for future role to be played by PML. Prez Parvez smartly promises future role for him. After Bhuttos now Shariff's remain. If these are with Prez then the game is over.
