Istanbul returned to the polls on Sunday in a re-run of the mayoral election that has become a test of Turkish democracy as well as President Recep Tayyip Erdogan’s continued popularity at a time of economic trouble. Election authorities annulled the first vote in March after Erdogan’s ruling party alleged corruption. Critics say Erdogan simply did not like the result, after a little-known former district mayor, 49-year-old Ekrem Imamoglu, snatched victory for the opposition by just 13,000 votes.