The legal principle that an officer or agent cannot delegate to another the powers confided to him, unless authorized to do so, is specially applicable to legislative bodies. Since the power to make laws is vested in the legislative department, and involves a large exercise of discretion and judgment to be discharged by those directly selected for that purpose by the people, it is properly insisted that the authority thus conferred cannot be transferred to any other person or body of persons, unless authorized by the constitution. Therefore, it is well settled that, unless in the state constitution there is some provision made for a referendum (see above, § 4), the legislature cannot make the validity of a statute depend upon the result of a popular election, in which the voters are asked to decide whether or not the proposed law shall go into effect (Rice v. Foster; Geebrick v. State). The constitutional power of the electors with reference to the making of laws, in the absence of a provision for referendum, is limited to the selection of members of the legislature, in whom the legislative authority is vested. For the same reasons, it is well settled that Congress cannot delegate to the president the power to determine whether or not a statutory provision shall become a law. While the president may in proper form approve or veto a bill which has passed both houses of Congress, he cannot be given authority, in his own judgment and discretion, to determine whether a proposed measure shall go into effect. A statute must rest for its authority on its lawful adoption by the houses of Congress and approval by the president, and not merely on the executive authority.

A distinction must be drawn, however, between the making of laws, and the provision, by means of laws duly made, for the exercise of authority and discretion by some officer or body, exercised in accordance with the provisions of such laws. Thus, the legislature of a State may by statute, duly enacted, leave it to be determined by vote in cities whether or not licenses for selling liquor shall be granted, and in counties whether domestic animals shall be allowed to run at large (Da/by v. Wo/f), and Congress may, by statute regularly passed, leave it to the president to decide whether retaliatory tariff duties shall be collected on goods brought from a particular country (Field v. Clark). Moreover, limited legislative authority may be directly conferred by a state legislature upon municipal corporations, such delegation of authority being within the implied powers of the legislative department, even though not expressly recognized in the constitution. (See below, § 97.)