Review was granted in this case to determine whether Proposition 36 violates equal protection principles by failing to make its mandatory probation requirement applicable to those who commit nonviolent drug possession offenses (NDPO’s) while on probation for offenses which are not NDPO’s. The Court of Appeal found that the language of Proposition 36 excluded those defendants, and that the omission denied equal protection because the requirement does apply to parolees who commit NDPO’s while on parole after completing prison terms for non-NDPO’s. To remedy this, the Court of Appeal construed the requirement also to apply to offenders who commit NDPO’s while on probation for non-NDPO’s. The Supreme Court disagreed that the exclusion of these offenders violates the right of equal protection and reversed the Court of Appeal’s judgment. Probationers on probation for non-NDPO’s are not similarly situated to parolees on parole for the same crimes. Parolees have had sentence imposed and have completed their prison terms for the non-NDPO. Probationers have not; they have not yet completed their conditional release which substitutes for the prison terms they would otherwise be serving. Therefore, the equal protection claim fails.