Turkey's newest warship displayed in front of Ottoman palace as symbol of regional power

President Erdogan campaigns on strong foreign policy, defense industry, and earthquake rehabilitation 

Challenger Ince advocates consensus, democratic reforms, and return to parliamentary democracy 

Election follows criticism of government's response to deadly earthquakes 

Economy, inflation, and cost of living are the most important issues for voters 

AKP party's two-decade rule saw emergence of conservative middle class 

Voters face choice between sharply different candidates and visions for Turkey's future 

Poll is predicted to be the closest in decades