Nigeria relatively little violence or voter fraud, in contrast to previous elections. In the March 2015 election, Muhammadu Buhari defeated Goodluck Jonathan by roughly 2 million votes. Observers generally praised the election as being fair. Jonathan was generally praised for conceding defeat and limiting the risk of unrest. Nigeria is a federal republic modelled after the United States, with executive power exercised by the President. It is influenced by the Westminster System model in the composition and management of the upper and lower houses of the bicameral legislature. The president presides as both head of state and head of the federal
Head of state bill to the Supreme Court to test its constitutionality, which are used under the president's discretion. The most extreme non-executive republican Head of State is the President of Israel, which holds no reserve powers whatsoever. The least ceremonial powers held by the President are to appoint the Prime Minister, to approve the dissolution of the Knesset made by the Prime Minister, and to pardon criminals or to commute their sentence. Some parliamentary republics (like South Africa, Botswana and Suriname) have fused the roles of the head of state with the head of government (like in a presidential system), while having