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 throne. Below follows a list of examples from different countries of general provisions in law, which either designate an office as head of state or define its general purpose. In the majority of states, whether republics or monarchies, executive authority is vested, at least notionally, in the head of state. In presidential systems the head of state is the actual, de facto chief executive officer. Under parliamentary systems the executive authority is exercised by the head of state, but in practice is done so on the advice of the cabinet of ministers. This produces such terms as "Her Majesty's Government"