Legal scholars are split as to whether those remarks were made in dicta. Most accept it as binding. The Justice Department guidelines for accepting clemency petitions requires that the petitioner "has accepted responsibility for his or her criminal conduct..."
A Pardon is NOT the same as a Clemency Petition:
A pardon is meant to indicate forgiveness of a particular crime, either because a person was wrongfully convicted or the punishment was not appropriate for the crime committed. A commutation is a merciful act offered when it is determined that the penalty given was too harsh. Pardon Vs Clemency