, ▁the ▁U . S . ▁government ▁had ▁no ▁constitution al ▁right ▁to ▁enter ▁into ▁a ▁treat y ▁concerning ▁game ▁reg ulation . ▁▁ ▁In ▁a ▁ 7 – 2 ▁decision , ▁the ▁Court ▁u ph eld ▁the ▁Act ▁as ▁an ▁exercise ▁of ▁the ▁federal ▁government ' s ▁treat y ▁power , ▁with ▁the ▁supre m acy ▁clause ▁of ▁the ▁Constitution ▁elev ating ▁treat ies ▁above ▁state ▁law . ▁The ▁Court ▁also ▁reason ed ▁that ▁protect ing ▁wild life ▁was ▁in ▁the ▁national ▁interest ▁and ▁could ▁only ▁be ▁accomplished ▁through ▁federal ▁action . ▁ ▁Missouri ▁is ▁also ▁notable ▁for ▁Justice ▁Oliver ▁Wend ell ▁Hol mes ' s ▁reference ▁to ▁the ▁legal ▁theory ▁of ▁a ▁living ▁constitution , ▁the ▁notion ▁that ▁the ▁Constitution ▁changes ▁over ▁time ▁and ▁adapt s ▁to ▁new ▁circumstances ▁without ▁formal ▁am end ments . ▁ ▁Fact s ▁Congress ▁had ▁previously ▁passed ▁laws ▁reg ulating ▁the ▁hunting ▁of ▁mig rat ory ▁water f ow l ▁on ▁the ▁basis ▁that ▁such ▁birds ▁naturally ▁migr ated ▁across ▁state ▁and ▁international ▁borders ▁freely , ▁and ▁hence ▁the ▁reg ulation ▁of ▁the ▁har vest ▁of ▁such ▁birds ▁could ▁not ▁real ist ically ▁be ▁considered ▁to ▁be ▁province ▁sole ly ▁of ▁individual ▁states ▁or ▁groups ▁of ▁states . ▁However , ▁several ▁states ▁object ed ▁to ▁this ▁theory , ▁and ▁twice ▁successfully ▁su ed ▁to ▁have ▁such ▁laws ▁declared ▁un const itution al , ▁on ▁the ▁prem ise ▁that ▁the ▁U . S . ▁Constitution ▁gave ▁Congress ▁no ▁enumer ated ▁power ▁to ▁reg ulate ▁mig rat ory