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[citation needed] 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 national executive; the leader is elected by popular vote to a maximum of two 4-year terms. In the March 28, 2015 presidential election, General Muhammadu Buhari emerged victorious to become the Federal President of Nigeria, defeating then incumbent Goodluck Jonathan.

What is Nigeria's form of government?