(photo: Mayor's Office/Kristen Artz)

There was an extraordinary turnout in New York City in the just-completed statewide Democratic primaries on Thursday, September 13. In the city alone, 855,000 Democrats came to the polls. That vote substantially exceeded the crowded and competitive 2013 Democratic mayoral primary (690,000), was nearly triple the city’s turnout in the 2014 Cuomo-Teachout primary (298,000), and came somewhat close to matching the Clinton-Sanders turnout in New York City of practically 1 million Democrats (996,000).

The good news about increasing voter participation may also foretell change in the dynamics of statewide elections. Democratic turnout in New York City was 57.3% of the statewide turnout of 1.49 million, a higher share than the geographic turnout model being used in two Siena Research Institute polls on the primary in July and September 2018, each of which assumed New York City’s share of statewide turnout would be 50%.

You might say ‘who cares about a bunch of polls?’, but polls are based on turnout from past elections, and those turnout models are also what candidates and campaigns use to allocate their time, energy, money, and resources. And, polls are frequently covered by the news media. If turnout in New York City is rising, campaigns must spend more money and time and volunteer effort there, and candidates’ positions must strongly appeal to residents of the nation’s largest city.

Turnout in the rest of the state also differed from the Siena Poll models. The final September poll modeled the turnout at 50% New York City, 13% suburbs, and 38% upstate. The actual results were 57% New York City, 18% suburbs, and 25% upstate. The number of Democrats outside New York City that came out to vote also rose substantially from 2014, more than doubling from 276,000 to 635,000, meaning there was far broader interest in the election this year across the entire state than in 2014. Cuomo won two-to-one in New York City, three-to-one in the suburbs, and 57-43% upstate.

While New York City had big increases in raw numbers and an increased share of the statewide primary vote, the real test of the city’s importance in statewide elections will now come in the general election. In the past three gubernatorial, off-presidential year elections -- 2006, 2010, and 2014 -- the city’s share of the statewide vote has been dismal.

Despite being 43% of the state’s population, the city’s share of the statewide vote in the past three general elections where the election for Governor was the top of the ticket has not reached 30%. In 2014, the city was 1 million of 3.8 million votes, a mere 26.5% of the vote. In 2010, when Governor Cuomo was first elected to the position, the city was 29% of 4.6 million votes. In 2006, when Eliot Spitzer won handily, the city was 28% of 4.4 million votes.

The question now becomes, was the surge in turnout in the city a one-off due to a few unique circumstances, or will it be sustainable because of a more engaged Democratic constituency in the age of Donald Trump?

[Read more: A Closer Look at Democratic Primary Turnout, Margins & Geography]