[20] In 2012, Markwell stepped down as Warden of Rhodes House to return to Australia, where his family lives, and to become the Executive Director of the Menzies Research Centre.
[21] As Executive Director of the Menzies Research Centre (a public policy think tank in Australia named for Australia's longest-serving Prime Minister, Sir Robert Menzies, and associated with the Liberal Party of Australia),[22] his activities included consultations with Julie Bishop for developing a 'New Colombo Plan' to encourage Australian university students to study abroad in Asia-Pacific universities,[23][24][25] and co-editing State of the Nation: aspects of Australian public policy.
[6] In October 2015, after the change of Prime Minister from Tony Abbott to Malcolm Turnbull, he became Senior Adviser to the new Leader of the Government in the Australian Senate, George Brandis, who was also Attorney-General of Australia, until December 2017.
[5] Markwell gave constitutional advice to the Prime Minister and Attorney-General during the prorogation, recall, and double dissolution of the Australian Parliament in 2016.
[28] In November 2017, it was announced that Markwell would become head of St Paul's College at the University of Sydney in early 2018.
[33][34] In July 2019 he was appointed Head of St Mark's College (University of Adelaide) from November that year.
[4][34] Portraits of Markwell hang at Trinity College, University of Melbourne, and Rhodes House, Oxford.
They address such questions as how to promote order and peace in the international society of states, the role of conventions in constitutional systems, and higher education for the 21st century.
[41] Markwell's writings in political science and public law have been especially concerned with constitutional issues, including federalism, constitutional conventions in the Westminster system, and the monarchy and republicanism in Commonwealth countries, including the reserve powers.