Voters in the nation’s most populous city head to the polls Tuesday to choose a new mayor for the first time in eight years. But it may be quite some time before we know who won New York City’s Democratic mayoral primary election.

Voters in the nation’s most populous city head to the polls Tuesday to choose a new mayor for the first time in eight years. But it may be quite some time before we know who won New York City’s Democratic mayoral primary election.