The president is the head of the state and executive body. He is also the commander-in-chief of the army and Navy of the USA. The president and vice-president are elected for a term of four years.
All the legislative power is vested in Congress, which consists of the Senate and the House of Representatives. There are 100 senators and 435 members in the House of Representatives. Two Senators from each state are elected by popular vote for a term of six years, the Representatives are elected for two-year term. Both houses must approve the bill for it to become a law.
An essential role in the US political system is played by the Supreme Court, which may declare a law, passed by Congress, to be contradictory to the Constitution of the country.
The various states have legislative and executive bodies of their own. Their structure, function and competence are determined by the Constitution of each state. There is an elected governor at the head of each state. States enjoy independence in their domestic affairs, including financial matters. However, state laws and actions of state authorities must not conflict with the Constitution of the USA.