James Manager was elected to the Senate on the People's Democratic Party ticket for the Delta South Senatorial District in 2007. He was appointed to the Works committee, Niger Delta committee and Judiciary, Human Rights and Legal Matters committee.
In May 2009, he raised the issue of the damage caused by the continued military bombardment of communities in the oil-rich Gbaramatu clan, Warri South Local Government Area of Delta State, leading to a senate resolution urging their Committee on Defence and Army to take action. He was joined in his protest against the violence by former Senator Fred Brume, who called it "an unequal battle that is drastically de-populating several parts of the region. In September 2009, Senator Manager urged President Umaru Yar'Adua to appoint someone familiar with the region as Minister of the newly created Ministry of Niger Delta.
Manager supported finding a diplomatic solution to the Joint Task Force attacks on Ijaw villages, saying war was not the right approach.
Manager successfully ran for re-election as Delta South Senator on the PDP platform in the April 2011 elections.