They–the corporations, the military industrial complex, the surveillance state, the monied elite, etc.–will not allow anyone to be appointed to the Supreme Court who will dial back the police state. They will not tolerate anyone who will undermine their policies, threaten their profit margins, or overturn their apple cart.
Scalia‘s replacement will be safe (i.e., palatable enough to withstand Congress‘ partisan wrangling), reliable and most important of all, an extension of the American police state.