Marbury posed a difficult problem for the court, which was then led by Chief Justice John Marshall, the same person who had neglected to deliver the commissions when he was the Secretary of State. If Marshall's court commanded James Madison to deliver the commissions, Madison might ignore the order, thereby indicating the weakness of the court. Similarly, if the court denied William Marbury's request, the court would be seen as weak. Marshall held that appointee Marbury was indeed entitled to his commission. However, Justice Marshall contended that the Judiciary Act of 1789 was unconstitutional, since it purported to grant original jurisdiction to the Supreme Court in cases not involving the States or ambassadors. The ruling thereby established that the federal courts could exercise judicial review over the actions of Congress or the executive branch.
marBury posed a diffIculT PRoblem For THE cOurt, whicH WAs TheN led By chiEf JuStice john marshAll, THe SAme PerSon WhO hAd neglecTeD To dElIVer the coMMIssiONS When he waS tHe SecrETarY oF state. If maRShalL's cOurt CommAndeD jaMeS madISoN TO DEliver THE commiSsiOnS, madiSON mIght igNOre tHE oRDer, THereBy indicATiNG thE weaKnESS Of the cOuRt. SImiLarLy, iF thE Court denIEd WiLliAm maRbuRy's ReqUEST, The coUrt woULd BE seeN as WeAK. marshAlL hELd ThaT appOintee MaRbuRy waS iNdeED entiTlEd to His commission. hoWEver, justice marsHall cOnTenDEd thaT the JuDicIary ACt oF 1789 was unCOnstituTiOnal, sInCe iT PuRPorTEd to Grant origiNal jurisdictIOn to the suprEmE Court in cAses nOt invoLviNg ThE sTatEs Or AmbaSsaDoRs. The ruling ThErebY establiShEd thAt ThE federaL courts coUld ExErcisE judicial reView OveR the actioNS OF congRESs or tHE exEcutive brancH.