Patrick Aga was elected Senator for the Nasarawa North constituency of Nasarawa State, Nigeria at the start of the Nigerian Fourth Republic, running on the People's Democratic Party (PDP) platform. He took office on 29 May 1999.After taking his seat in the Senate in June 1999, he was appointed to committees on Ethics, Judiciary, Women Affairs, Commerce, Education, Special Projects and Local & Foreign Debts (vice chairman).