What a government of limited powers needs, at the beginning and foreve
r, is some means of satisfying the people that it has taken all steps
humanly possible to stay within its powers. That is the condition of i
ts legitimacy, and its legitimacy, in the long run, is the condition o
f its life.(1) Our whole political system rests on the distinction bet
ween constitutional and other laws. The former are the solemn principl
es laid down by the people in its ultimate sovereignty; the latter are
regulations made by its representatives within the limits of their au
thority, and the courts can hold unauthorized and void any act which e
xceeds those limits. The courts can do this because they are maintaini
ng against the legislature the fundamental principles which the people
themselves have determined to support, and they can do it only so lon
g as the people feel that the constitution is something more sacred an
d enduring than ordinary laws, something that derives its force from a
higher authority.(2)