As we previously commented, though the man who has dominated the nation's politics for almost two decades is not expected to lose, a consensus is emerging that the vote should be regarded as a referendum on his person and leadership.
And now, a visible surge in popularity for the rival secularist Republican People's Party (CHP) candidate has pundits declaring the opposition actually has a chance.
Erdogan has often boasted that he has never lost an election and, as recent polls indicate, he is unlikely to lose this time either (but likely by a thin margin). Since 2002, he and his AKP (Justice and Development Party) have won five parliamentary elections, three local elections, three referendums and one presidential election.
The president moved elections that weren't supposed to be held until 2019 forward by more than a year in hopes of smashing an unprepared opposition, but there's yet a possibility this could backfire.