A presidential system is a system of government where an executive branch is led by a president who serves as both head of state and head of government. In such a system, this branch exists separately from the legislature, to which it is not responsible and which it cannot, in normal circumstances, dismiss.
Presidents take more direct personal charge of policy than the cabinet does in a parliamentary system. The majority party and the cabinet are a team in a parliamentary system. But the president is directly elected by the people. Unlike parliamentary cabinets, the presidential cabinet does not contain party notables. The president is also the head of the army and directly responsible for foreign policy.
Presidents in presidential systems are always active participants in the political process, though the extent of their relative power may be influenced by the political makeup of the legislature and whether their supporters or opponents have the dominant position therein. In some presidential systems such as South Korea or the Republic of China (on Taiwan), there is an office of the prime minister or premier, but unlike semi-presidential or parliamentary systems, the premier is responsible to the president rather than to the legislature.
On September 6,1787, the Founders in Philadelphia abandoned their plans for parliamentary governance in favor of a presidential system. The presidential system, with its separation of powers among the different branches of government, is at the core of the Constitution. James Madison thought that presidential systems are more likely to preserve liberty.
It is hard to make comprehensive policies in a presidential system than in a parliamentary system because a bill can be blocked at any stage in a presidential system, the governments are relatively slow to respond. Responsibility for policy is more difficult to identify ina presidential system because it is hard to blame anyone: the President, the Congress or the Supreme Court. However, presidential systems tend to be more efficient for large countries.
In presidential systems, presidents, combining the roles of head of state and head of government, are dominant in the executive, but due to an institutional separation of powers they have to find majority support for their policy preferences on an issue-by-issue basis in the legislature.
Presidentialism alone is neither a necessary nor a sufficient condition for democratic instability. Presidential constitutions, because they are designed to create checks and balances by pitting one branch of government against another, may set in motion characteristic patterns of political struggle involving sharp disputes over the powers of the president, the legislature, and the courts when other forces trigger a crisis.
Compared to parliamentary systems, the presidential system suffers less from the danger of oppression of minorities since votes are led by issues that concern the majority. The presidential system is better from the point of view of accountability since executive can be directly voted down.
Presidential systems possess several defining features including the separation of power between the executive and the legislative branches of government, weak party discipline, and a powerful committee system. Presidential systems, first devised in the United States as an alternative to the monarchical system, are characterized by a separation of powers. Not only do the executive and the legislature exist independently of one another, but they are also elected independently of one another.
Presidential Republic is the form of government in which sovereignty is vested in the people and their elected or nominated representative (president). A presidential republic may also be understood to be a state in which all segments of society are enfranchised and the power of the state is limited.
In a presidential system, the president is popularly elected, either directly or indirectly, and holds office for a fixed term. The legislature cannot remove the president from office, except by impeachment.