Presumption of constitutionality

In determining whether the legislature, in a particular enactment, has passed the limits of its constitutional authority, every reasonable presumption must be indulged in favor of the validity of such enactment. It must be regarded as valid unless it can be clearly shown to be in conflict with the Constitution. It is a well-settled rule of constitutional exposition that, if a statute may or may not be, according to circumstances, within the limits of legislative authority, the existence of the circumstances necessary to support it must be presumed.