WRIGHT— LIMITATIONS UPON STATE POWERS. 171 



in time of peace the exercise of foreign relations powers has shown 

 a tendency to narrow state power. Thus Congress has extended 

 the jurisdiction of federal courts over many cases involving treaty 

 interpretation, over numerous controversies where aliens or persons 

 especially protected by international law are parties, and over many 

 offenses against international law and treaty. Congress has also 

 given national officers authority to enforce such treaties as those 

 protecting migratory birds, and fish in boundary waters, and those 

 requiring extradition of criminals and prohibition of the white slave 

 traffic. Many self-executing treaties have limited state power 

 without congressional action such as those according property and 

 personal rights to aliens. ^^ 



Although this limitation of state powers by action of national 

 organs has been a patent phenomenon, its constitutionality has been 

 questioned, especially so far as effected through exercise by the 

 national government of its power over foreign relations. Thus it 

 has been alleged that all state powers are not merely residual but 

 that some, for instance the police power, are " reserved " powers 

 incapable of limitation by any exercise of its delegated powers by 

 the national government. It will readily be seen that this notion is 

 wholly incompatible with the principle of national supremacy and 

 while it has great historic importance, it never commanded whole- 

 hearted support from the courts and at present enjoys no legal 

 recognition.^- The concept of " reserved " powers is, however, of 

 importance as an " understanding " of the Constitution. In practice 

 both Congress and the treaty-making power have sometimes re- 

 frained from fully exercising their powers out of respect for state 

 susceptibilities, and the courts have sometimes given rather strained 

 interpretations to treaties for the same reason. ^^ 



We may conclude that state exercises of power in the field of 

 foreign relations have been so restricted that such powers hardly 

 exist at all. 



1^ See Corwin, National Supremacy, N. Y., 1913; Sutherland, Constitu- 

 tional Power and World Affairs, N. Y., 19 19. 

 ''■-Infra., sees. 48-51. 

 13 Infra, sec. 50. 



