He lectured at Flinders University from the early 1970s until retirement in 2001, he remains an adjunct Professor with the Department of Politics and Public Policy. For decades he was prominent political commentator/psephologist for the Australian Broadcasting Corporation and a frequent contributor to local radio in South Australia. Currently, Jaensch is a columnist for The Advertiser newspaper and an occasional lecturer at the Flinders University. He continues to act speak on public affairs and the machinations of State and national government. Jaensch advocates proportional representation and an end to compulsory voting in Australia (though not necessarily compulsory enrolment).