Turkey awaits presidential election results

Election polls closed Sunday in Turkey, where President Recep Tayyip Erdogan's 20-year leadership of the NATO member country grappling with economic turmoil and the erosion of democratic checks-and-balances hung in the balance after a strong challenge from an opposition candidate.

The election could grant Erdogan, 69, a new five-year term or unseat him in favor of the head of an invigorated opposition, Kemal Kilicdaroglu, who has promised to return Turkey to a more democratic path. If no candidate receives more than 50% of the vote, the race will be determined in a May 28 run-off.

Voters also elected lawmakers to fill Turkey's 600-seat parliament, which lost much of its legislative power under Erdogan's executive presidency. If his political alliance wins, Erdogan could continue governing without much restriction. The opposition has promised to return Turkey's...