Parliamentary, Presidential, and Semi-Presidential Systems
Until that point, the close connection between the executive and the legislature and the blurring of the separation of powers in the parliamentary system is manifest.
In the parliamentary system, the government and parliament work together. The former must have the support of the latter in making decisions, given its dependence on it. During this time, Congress will pay attention to (discussing and adopting) the government bills, along with proposals that emerge from their seats. Furthermore, as an expression of that dependence, the parliament controls the action of the government through various parliamentary mechanisms (from written questions to the chairman of executive control in the full House, leading to a motion of censure).
The membership of the government is usually one of the features that characterize this type of system. The president, who has received the confidence of parliament, usually has the responsibility of electing ministers with him to serve on the council of ministers, taking the chairman’s role among equals. The responsibility is collective, although the president has a prominent role in both authority and political responsibility.
In most parliamentary systems, the Head of State adopts purely symbolic functions, having reserved arbitration and mediation functions between the executive and legislative branches.
Presidential Systems
In presidential systems, there are two powers with direct legitimacy: the parliament (which has the legislative function) and the President (of the State, who serves as the executive), elected by citizens in separate elections. There is a clear separation of powers. Thus, there are no parliamentary control mechanisms on the president, while he has no power to dissolve Congress and call new elections. The president has full authority to appoint members of the government, who sometimes have only the status of advisers, as only he is responsible for making policy decisions to the electorate.
The double source of legitimacy and distinct designation mechanism may lead to a scenario in which the parliamentary majority is of a different political persuasion than the president, which may lead to institutional blockages. These are usually solved with the pre-eminence of parliament, which is able to veto legislation to the president. Also, the president can veto certain laws that the legislature wants to pass. This system can also lead to populist practices that may come to undermine the normal functioning of democratic institutions.
Semi-Presidential Systems
The semi-presidential system is an intermediate range in which the president and the legislature have a meeting space in government. The Prime Minister is appointed by him but must have the confidence and responds (is vested and may be censored) to parliament. In this type of system, a Head of State, elected by direct universal suffrage, coexists with considerable executive powers (including sharing with the executive the power to dissolve the Chambers) and a Prime Minister and a government responsible to parliament, although nominated by the president.
The influence of parliamentarism is perceived in the political control exercised by the government on the parliamentary chambers. The influence of presidentialism is felt in the active role in executive function played by the president, who may even remove the prime minister. It is also possible in this type of mixed system that a president and a parliamentary majority (and thus a prime minister) of different political inclinations cohabit. Thus, the president’s power, as in the previous case, will be greatly diminished by the parliament.
Territorial Structure of Political Power
The birth of the modern state led to the unification of power that ended the atomization of medieval political power. The result was the formation of centralized unitary states in which the only source of power dictated laws applicable throughout the territory.