Nkrumah's complete domination of political power had served to isolate lesser leaders, leaving each a real or imagined challenger to the ruler. After opposition parties were crushed, opponents came only from within the CPP hierarchy. Among its members was Tawia Adamafio, an Accra politician. Nkrumah had made him general secretary of the CPP for a brief time. Later, Adamafio was appointed minister of state for presidential affairs, the most important post in the president's staff at Flagstaff House, which gradually became the center for all decision making and much of the real administrative machinery for both the CPP and the government. The other leader with an apparently autonomous base was John Tettegah, leader of the Trade Union Congress. Neither, however, proved to have any power other than that granted to them by the president.

By 1961, however, the young and more radical members of the CPP leadership, led by Adamafio, had gained ascendancy over the original CPP leaders like Gbedemah. After a bomb attempt on Nkrumah's life in August 1962, Adamafio, Ako Adjei (then minister of foreign affairs), and Cofie Crabbe (all members of the CPP) were jailed under the Preventive Detention Act. The CPP newspapers charged them with complicity in the assassination attempt, offering as evidence only the fact that they had all chosen to ride in cars far behind the president's when the bomb was thrown.

For more than a year, the trial of the alleged plotters of the 1962 assassination attempt occupied center stage. The accused were brought to trial before the three-judge court for state security, headed by the chief justice, Sir Arku Korsah. When the court acquitted the accused, Nkrumah used his constitutional prerogative to dismiss Korsah. Nkrumah then obtained a vote from the parliament that allowed retrial of Adamafio and his associates. A new court, with a jury chosen by Nkrumah, found all the accused guilty and sentenced them to death. These sentences, however, were commuted to twenty years' imprisonment.

In early 1964, in order to prevent future challenges from the judiciary, Nkrumah obtained a constitutional amendment allowing him to dismiss any judge. At the same time, Ghana officially became a single-party state, and an act of parliament ensured that there would be only one candidate for president. Other parties having already been outlawed, no non-CPP candidates came forward to challenge the party slate in the general elections announced for June 1965. Nkrumah had been re-elected president of the country for less than a year when members of the National Liberation Council (NLC) overthrew the CPP government in a military coup on February 24, 1966. At the time, Nkrumah was in China. He took up asylum in Guinea, where he remained until he died in 1972.

Data as of November 1994