Emmanuel Ocheja first showed his interest in politics in 2003 when he sought the nomination of the People’s Democratic Party to contest for the governorship seat of Kogi State against the incumbent Prince Abubakar Audu of the All Nigeria Peoples Party. He lost to Alhaji Ibrahim Idris in April 2003. In 2005, President Olusegun Obasanjo appointed him to serve as the Chairman of the board of directors of the Integrated Data Services Limited (IDSL: A subsidiary of the NNPC). He returned to Kogi State politics in 2008 to serve as the Chairman of the state chapter of the People’s Democratic Party. 

In late 2010, he declared his intention to contest elections into the National Assembly of Nigeria to serve as Senator in the 7th (2011–2015) session under the platform of the People’s Democratic Party. He won the general elections against his main challenger Attai Aidoko Usman who flew the flag of the All Nigeria Peoples Party. In 2014, Ocheja resigned his membership of the People’s Democratic Party citing his disagreement with certain power blocs within the party as well as poor governance by some political office holders elected on its platform. He formally announced his membership of the opposition All Progressives Congress (APC) on 7 February 2015 even though he was known to have joined the party long before then. At the event of his decamping, he pledged to work towards delivering victory to all the candidates seeking electoral offices on the platform of the APC in Kogi State. 

He maintained his membership of the APC and campaigned for its candidates throughout Kogi state in the buildup to and during the election. As a believer in President Muhammadu Buhari and his government, Ocheja used several ways to sensitize the electorate in Kogi on why the president had to be re-elected. In September 2018, Ocheja was sworn in as one of the chairmen of the APC committees for the governorship primaries of the party. He led a team with six other members to conduct the exercise in Taraba state