Then-Manhattan Borough President David Dinkins and former U.S. attorney Rudolph Giuliani debate during the 1989 race for mayor, which achieved 60 percent turnout -- the highest of the city's post-fiscal-crisis period.

Election 2017 is fading into memory but the debate about what it really meant continues.

“A day after winning reelection with 66 percent of the vote, Mayor de Blasio declared that the voters had given him ‘a mandate,'” wrote Greg Smith in the Daily News last Wednesday. “In terms of margin of victory, that was certainly true. But 66 percent of what?”

Later in the week, the Daily Beast’s John Avlon said the 2017 results reflected “the dangers that come with life in an essentially one-party town.”:

Only 24 percent of registered voters in New York bothered to turn out. That’s a record low—a far cry from the 40 percent when Rudy Giuliani won big in his bid (which I worked on) for a second term or the 41 percent who showed up two months after the Sept. 11, 2001, terror attacks, when Mike Bloomberg narrowly beat Mark Green, solidifying 20 years of Republican and independent mayoral rule that drove New York City’s resurgence. De Blasio has been an uninspiring and largely unpopular play-to-the-base mayor, struggling to get above 50 percent job approval. But crime has stayed down thanks to the NYPD and the economy has hummed along. While de Blasio keeps slipping on banana peels in his many attempts to cast himself as the mayor of progressive America, Donald Trump’s election a year ago and the reactionary cast of today’s Republican Party virtually guaranteed that he would be reelected in the absence of a narrowly missed indictment.

The mayor, meanwhile, had a dramatically different interpretation of the election 2017 numbers:

So, yesterday, the people of New York City delivered a message loud and clear, they delivered a mandate. It’s a mandate for fairness to make this the fairest big city in America. I’m very humbled to accept that mandate and to turn it into a reality. People want this to be a more just place. They want this to be an inclusive place, a place of opportunity for all. And there’s a deep sense all over the city that we need to keep what is great about New York, great for generations to come. It needs to be a place for everyone and it needs to be an open place not a place that becomes exclusive. And that’s the mandate I’m ready to act on right away …

Reality supports neither the extremely harsh interpretation Avlon offers nor the rosy spin the mayor has pushed.

De Blasio’s winning percentage of 66 percent was higher than the vote share that David Dinkins, Rudy Giuliani or Michael Bloomberg won in any of the six elections in which those mayors prevailed. It’s also higher than Andrew Cuomo received statewide in 2010 or 2014. De Blasio nabbed about 140,000 more votes than Bloomberg did in 2009 and roughly 110,000 more than Giuliani did in 1997. Yes, the city is larger now, but that’s still a decent margin.

However, de Blasio’s 2017 vote total appears to have been 70,000 shy of his own 2013 total, which is a big drop. And the turnout numbers that Smith and Avlon are correct. 2017 appears to have set a record for the lowest turnout in modern history. That’s nothing to celebrate.

A key thing to note is that turnout was down in 2017 not because fewer people voted—in fact, about 10,000 more people cast ballots in the mayoral race this year than in 2013—but because a lot more people are registered. The number of active voters in the city is 8 percent higher now than it was four years ago, around twice as fast as city population is growing.

However, 24 percent turnout is still really, really low turnout.

But you’d have to strain to see this as a reflection on de Blasio or on New York’s status as a one-party town, because the problem has been developing for decades, spanning other mayoralties, including the 20 years when New York City mayoral races were won by Republicans. (The figures behind this chart were computed by the New York City Board of Elections for its 2013 annual report, except for the 2017 number, which I added based on NYCBOE’s preliminary results and NYSBOE’s enrollment information):

So, pathetic mayoral turnout is nothing new. But it is getting worse. And that is not confined to the mayoral races. These figures about gubernatorial races also come from the Board of Elections (except for the 2014 figures, which I gathered):

Even presidential elections are drawing a smaller share of the voting pool:

Elections have consequences. The fact that some people did’t show up to cast a ballot doesn’t undermine what the folks who did their civic duty decided. De Blasio has a mandate to govern as strong as any mayor before him.

But New York City has a problem, and it’s bigger than 2017 or the current mayor. People are tuning out of democracy. The political class—including de Blasio—owns a large share of responsibility for that (the media, pop culture and others also get blame). But the canary in the coal mine isn’t that turnout is down four points since the whopping 28 percent Bloomberg attracted in 2009; it’s that three out of five voters have stayed home on Election Day for six straight New York City elections.

The dismal turnout last Tuesday is not primarily a stain on de Blasio. It’s a pox on all our houses.