Government is the system through which a nation or state, a city, township, or community exercises authority and enforces its laws. Governments can be established for a variety of purposes, such as providing security, maintaining infrastructure, and promoting economic prosperity. Governments can also act as a provider of goods and services that the private sector cannot or will not provide, such as public education, police and fire departments, or public parks. Government can also redistribute wealth by imposing taxes and other forms of taxation to fund programs for the benefit of some groups of citizens at the expense of others.
Governments vary in size, structure, and function from one country to another. They can be based on a single person (an autocracy) or on a select group of people (an aristocracy). In some cases, they can be based on the majority of the population (a democracy). They can be centralized, with power vested in the hands of a few individuals (a monarchy) or spread more evenly among the population (a republic).
There is a role for government to play in a market economy whenever its benefits outweigh its costs. For example, governments often make investments in the national defense, address environmental concerns, define and protect property rights, and try to make markets more competitive. But when government steps over this line into the aggressive redistribution of wealth by redistributing income through taxes and social welfare programs, it becomes a lever of unlimited power that is sought after by unscrupulous individuals and pressure groups trying to fatten their pockets or gain control of a machine they can use to accomplish their goals.
The founders of the United States envisioned a federal system that would diffuse power by breaking it down into three branches: the legislative, executive, and judicial. The legislative branch is responsible for making laws and appropriating the money to operate government. The executive branch, led by the president, is responsible for enforcing the policies laid out by Congress and overseeing our foreign policy. The judicial branch, made up of the Supreme Court and other federal courts, interprets the laws and decides whether they are constitutional.
The local level, involving the city council or board of supervisors, is on the bottom rung of the ladder and makes decisions for its specific region. The next rung up is the state legislature, which in the United States has two chambers—a smaller upper house called the Senate and a larger lower house that is usually called the House of Representatives. The lone exception is Nebraska, which has a unicameral legislature. The top rung is the national level, which in the United States is framed by the Constitution and the legislative branch. The national, state and local levels are all interconnected but each level cannot pass laws that conflict with the decisions/laws of the level above. This is known as the law of interlocking obligations.