Legislature, branch of government empowered to make, change, or repeal its laws and to levy and regulate its taxes. Most modern legislatures are representative: composed of many members who are chosen directly or indirectly by popular vote. Legislatures that provide direct representation are usually considered more democratic in practice because they are less susceptible to being dominated by a single faction.
Many modern governments have a bicameral, or two-house, legislature. The so-called lower house is generally elected on a basis of direct representation; and the upper house commonly on a basis either of indirect representation or of direct representation limited to certain occupational, territorial, or hereditary categories. The traditional theoretical justification for an upper house is that it can exercise moderation and delay on legislation by the lower house and thus restrain the effects of impulsive or excessive fluctuations of public opinion. A number of governments, however, have unicameral, or single-house, legislatures.
The various legislatures throughout the world are known by different names, such as Congress, Parliament, Diet, and Assembly. Most are limited in their powers by the Constitution or organic law of the government of which they are a part. The enactments of the United States Congress, for example, can be vetoed by the president, and the Congress must approve by a two-thirds majority any bill it wishes to pass despite a presidential veto. The British Parliament, on the other hand, chooses its own prime minister and Cabinet, who are ultimately responsible for it for all their administrative actions. Being legislative as well as executive or administrative leaders, these officials have considerable power to initiate and influence legislation desired by their administrative departments. The tendency in most modern governments has been towards increasing assumption of legislative powers by administrative officials, with a consequent weakening of the legislatures. Many political scientists ascribe this to growing public impatience with the uncertainties of party politics within legislatures. The trend is also attributed to the increasing complexity of modern government, which requires the use of people with specialized skills, often not found in publicly elected legislatures, for the drafting of laws.