Only a total moron would come to the US expecting a fair trial, after literally being called a traitor worthy of the firing squad or life imprisonment by major politicians on broadcast TV. And only a total moron would expect an after the fact pardon either. Heck, only a moron would expect the state to even honor a plea bargain made, if the bargain was made while the State did not actually have Snowden in custody. So I doubt it will come to this. Only way I see Snowden ever returning to US soil is if a very progressive set of politicians take power 20 years from now, and they pardon him before he ever tries to return.