[6] In November 1982, he was hired as a research and teaching fellow at the Faculty of Law of the University of Athens.

[9] Kaminis, who ran as an independent,[10] had been nominated by the small, newly formed Democratic Left party and was also backed by the country's ruling Panhellenic Socialist Movement, the Ecologist Greens and Portokali (Drassi and the Liberal Alliance).

He was the first left-of-centre candidate elected mayor of the Greek capital, historically a conservative stronghold, in more than two decades.

On 24 February 2018, he announced the formation of a political tendency called Renewal (Greek: Ανανέωση) within the Movement for Change, a nascent political alliance of centre-left parties formed around PASOK.

[13] On 7 July 2019, he was one of the 12 candidates elected to the Hellenic Parliament through party-list proportional representation.