What difference should the New York City mayoral race make to you if you live elsewhere? Well, New York is still New York, and what happens there matters. There’s more. As fate would have it, this is a particularly interesting year: This is the year that it finally seems likely that after two decades in purgatory, the Democrats will take back City Hall. And it’s starting to look like the person who’s going to do it is Bill de Blasio, who just vaulted to the head of the pack in recent polling.

De Blasio is the most liberal-populist of the leading Democrats, and he is crystal clear that a de Blasio mayoralty won’t be so much about underwriting the “job creators” or making Midtown prettier for the folks coming in from Westchester to see Kinky Boots, but about trying to help the people who clean up after both of those groups. Is New York ready for that change, and is de Blasio the agent of New York City liberalism’s rebirth?

Let’s first go back in time. In its default mode, going back to Boss Tweed’s day or even before, New York City was run by Democrats. But once a generation or two, when the stench of corruption became utterly unignorable, Republicans who fashioned themselves reformers would be given their chance. A hundred years ago, it was Seth Low, who had also been a president of Columbia University. Thirty years later and far more famously came Fiorello La Guardia. By that time, New York City had a number of small political parties, some of them based around labor unions, and various independent groups. The Little Flower was a Republican, but a liberal (different times), and he enjoyed backing from both the GOP and these labor and independent leaders. This was “Fusion”—a coalescing of all the reform tendencies behind one man to defeat the corrupt Democrats.

The next Republican Fusionist was John Lindsay in the ’60s. After his eight years, the Democrats came back in—Abe Beame, then Ed Koch, then David Dinkins. And then came Rudy Giuliani, who beat Dinkins in 1993. If matters had followed the historical pattern, Giuliani would have served his two terms, after which the Democrats would have recaptured the reins, and the normal process would have repeated itself.

But then Mike Bloomberg, improbably, ran—as a Republican, even though he had been a registered Democrat (and was a pretty liberal one). More improbably still, he won. And kept winning. The Democratic exile would continue for 12 more years, making 20 in all—an out-of-power interregnum without precedent in the city’s history. It happened for reasons too numerous to go into, but they all added up to the suspicion among the city’s new upper-middle class, which grew after the 1970s nadir and prospered in the go-go ’80s and ’90s, that the Democrats would screw things up again.

But this year, there is no Fusionist savior—just two GOP candidates who, though one is very rich and the other worked for Giuliani, leave a lot to be desired. There is a sense as there has not been for nearly 30 years that the winner of the Democratic primary will probably be mayor.

In the latest public poll, de Blasio has jumped to a fairly substantial lead among Democrats, and he defeats his Democratic opponents in potential head-to-head matches (there’s a runoff between the top two finishers if no one gets 40 percent on September 10). So I asked him yesterday (and I should note that I’ve known him since 1989) whether he is, in the context of all the above, the man for the times.

“The story of our times,” he said, “begins with the economic crisis.” He cited a statistic he cites often—that 46 percent of New Yorkers are living at or below 150 percent of the poverty level. That’s $35,325. The median rent in Brooklyn, nearly $2,600 a month, comes to $32,000 a year. Obviously, these folks aren’t paying rents close to that median, but the figures give us an idea of how these New Yorkers have to live in that crazy-expensive city. De Blasio is the 46 percent’s candidate and makes no bones about it. “Mayor Bloomberg,” he told me, “opposed a living-wage bill, opposed paid sick days, had no jobs creation program ... he opposed every opportunity to do something to alleviate inequality.”

I asked what lessons he and New York Democrats generally needed to learn from their wilderness years. Here, a Democrat is “supposed” to say things that will reassure the chattering classes: that public safety is still job No. 1, that the party became too devoted to its special interests, and so on. De Blasio went in the opposite direction. “We became too timid,” he said. Too afraid to assert an aggressive economic populism.

There are only three serious Democratic candidates now, with Anthony Weiner having mercifully faded. It’s either de Blasio or City Council Speaker Christine Quinn or former Comptroller Bill Thompson. Quinn’s accommodations to Bloomberg over the years have left a lot of Democratic activists cold, and Thompson has Al D’Amato raising money for him. All that makes de Blasio pretty attractive to more liberal Democratic primary voters by comparison, so he ought to make a runoff against one or the other.

The establishment—the Real Estate Board of New York and other entities—will be for whomever that is. DeBlasio ain’t their guy, to put it mildly. He can survive that, maybe. But to win a runoff, or certainly a general, he’s going to need to demonstrate to those jittery upper-middle-class New Yorkers that his agenda will produce benefits for them, too.

These are mostly registered Democrats who would never dream of voting Republican nationally but who voted in large numbers for Giuliani and Bloomberg. They decide New York elections. Has crime been low enough for long enough for these voters to decide that the city appears likely to stay safe no matter who’s running it, and it’s time now to address other problems? That’s the case de Blasio needs to make. It’s a case that can be easily fear-mongered from the other side, so how he stands up to that may determine whether the interregnum continues.