Under the scope of EU-Turkish relations, the EU stance of the Republican People's Party has been scrutinized under the two party leaders: Baykal and Kiliçdaroglu. After giving basic information on rotation of the EU-Turkish relations, the CHP's historical development and party ideology have been discussed. It is argued that the CHP classifying itself as a European social democratic party today, until recently under Baykal's leadership has maintained its traditionalist, authoritarian and nationalist (TAN) feature and employed a euro-skeptic stance in several cases. However, it is claimed that under Kiliçdaroglu's leadership, the party has gained a more green, alternative and libertarian (GAL) identity. With respect to this, first it has been researched that if the party's euro-skeptic stance has changed, and respectively it has been found out that except for some endogenous factors (national cost benefit calculations regarding the EU membership), the party's hard line stance has not been influenced with this shifting of the party ideology. However, the paper also critically assesses the party's EU stance by testing its legitimacy and reasonability.