In 2000, he returned to Turkey and started working at the Center for Eurasian Strategic Studies on the Caucasus region.

Oğan organized opposition to the 2017 Turkish constitutional referendum resulting in his final expulsion from the Nationalist Movement Party.

Prior to this, he was a challenger against Devlet Bahceli, leader of the MHP, where an internal revolt had occurred due to the party's poor showing in the November 2015 Turkish general election.

[9] Oğan argued that the MHP platform was against "constitutional change" and campaigned against Bahceli's support for the referendum.

Oğan was subject to an alleged assassination attempt after his expulsion from the party, though the district governor of Samsun Province disputed this claim.

[10] He was nominated as the ATA Alliance candidate for the 2023 Turkish presidential election, acquiring the necessary 100,000 signatures to stand on 26 March 2023.