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
Constitution of Nigeria British order in council so as to come into force immediately upon independence, on 1 October 1960. Under this constitution Nigeria retained Queen Elizabeth II as titular head of state. Independent Nigeria's second constitution established the country as a federal republic. It came into force on 1 October 1963 (Nigeria's third anniversary as an independent nation). The 1963 constitution, which was based on the Westminster system, continued in operation until a military coup in 1966 overthrew Nigeria's democratic institutions. The 1979 constitution, which brought in the Second Republic, abandoned the Westminster system in favour of an American-style presidential system, with