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 parliamentary systems, and in some presidential systems, however, the head of state may do so on their own initiative. Some states have fixed term legislatures, with no option of bringing forward elections (e.g., Article II, Section 3, of the U.S. Constitution). In other systems there are usually fixed terms, but the head of state retains authority to dissolve the legislature in certain circumstances. Where a head of government has lost support in the legislature, some heads of state may refuse a dissolution, where one is requested, thereby forcing the head of government's resignation. In the Commonwealth realms, other than the