GWEN IFILL: Yesterday marked the beginning of the end of a political era in the nation's largest city.

Democrats delivered a rebuke to outgoing New York Mayor Michael Bloomberg, choosing one of his chief critics, Bill de Blasio, as their nominee.

The city's public advocate finished first, but he may not have achieved the 40 percent threshold needed toavoid a runoff.

Former City Comptroller William Thompson placed second. Former Congressman Anthony Weiner, meanwhile, finished a distant fifth.

On the Republican side, former Transit Authority head Joe Lhota won with more than 52 percent of the vote.

Hari Sreenivasan examines what's next for a post-Bloomberg Big Apple.

HARI SREENIVASAN: The next mayor of New York will inherit a city that in many ways has been transformed during Michael Bloomberg's 12-year tenure.

By several measures, New York City is thriving.

Its economy is growing, crime is at historic lows, and the city's eight million residents are healthier and living longer than a decade ago.

Michael Powell has reported on the city for more than 20 years.

He's now a columnist at The New York Times.

He says, when Bloomberg took office, right after 9/11, the city's future was far from secure.

MICHAEL POWELL, The New York Times: He really took control of a city that was a wounded animal, and, at his best, both nursed it back to health and in many ways transformed the city.

HARI SREENIVASAN: The city's financial health is one area where the mayor generally gets credit.

New York City's budget, which is $70 billion this year, has been in the black throughout Bloomberg's tenure.

Mitchell Moss teaches urban planning at New York University and was an adviser to Bloomberg during his first run for mayor.

Moss argues that Bloomberg's tax policies have not only stabilized the city's economy, but helped it survive the great recession.

MITCHELL MOSS, New York University: When Mike Bloomberg came in, we had become very dependent upon the income and sales tax. But they're very much tied to economic activity, more income, more taxes, more spending, more taxes.

Bloomberg came in and a year after taking over, he raised the property tax.

Now, this is a very important issue because the property tax is largely a tax on office buildings and homeowners, and most mayors don't want to do this because the real estate industry is too strong and homeowners are very active voters.

And that created a new stable set sort of revenue.

So, when 2008 occurred, we weren't like the state of California, which was in dire straits.

Yes, income taxes weren't growing, but our property taxes were.

HARI SREENIVASAN: Even so, like many cities, New York faces huge and growing costs for the pensions and health benefits of city employees, which will run into the billions of dollars.

Additionally, according to economist and professor at the New School Richard McGahey, the next mayor will have to negotiate long overdue contracts with the city's unionized workers.

RICHARD MCGAHEY, The New School for Social Research: They have been working without a contract, most of them for over three years.

And there are pent-up demand to get more wages, up to $8 billion to $10 billion.

And there is no provision in the budget to pay for those.

So the next mayor is going to be right at the start having to negotiate with a fairly angry coalition of unions across the board.

HARI SREENIVASAN: So, what about the fiscal health of the city's residents?

Unemployment is 8.4 percent, a point higher than the rest of the country.

New York's real estate boom continues.

The median value of a home across the industry's five boroughs is half-a-million dollars, nearly triple the national average.

That's great for landlords and homeowners, but two-third of New Yorkers rent, and sky-high rents eat up a larger percentage of wages here than elsewhere.

MICHAEL POWELL: So what does this mean?

If you're a secretary married to somebody who is working in a restaurant, the day-to-day struggle to find an apartment that you can afford is enormous.

For instance, in the Bronx, I believe the average family spends upward of 40 percent of their income on rent. That's very troubling, because it means that they have very little money left over for food. It's one of the reasons you have seen a very sharp increase in food stamp usage in New York.

HARI SREENIVASAN: While New York is home to more billionaires than nearly any place in the world, according to the city's own data, over 20 percent of residents here live below the poverty line and another quarter live just above it.

The homeless population in New York has also grown in recent years to more than 50,000 people.

RICHARD MCGAHEY: New York inequality is really quite staggering.

If you compare the incomes of the top 20 percent to the bottom 20 percent, our income ratios are worse than many developing African countries.

Now, that's because we have rich people here. It's not bad to have rich people in New York.

We want them here.

But what we need is a smarter economic development strategy that will use the city's economic strength to create good jobs for low-income people.

HARI SREENIVASAN: Perhaps the most enduring legacy the next mayor will inherit is how safe New York Cityis today.

For those who lived here in the '70s, '80s, and '90s, the drop in crime is nothing short of remarkable.

While crime had fallen sharply during Rudy Giuliani's administration, it has continued to do so under Bloomberg.

Since 2001, car thefts are down 73 percent, burglaries 41 percent, assaults 17 percent, rapes 27 percent, and murders are down 35 percent.

NYU's Mitchell Moss argues that the city's drop in crime goes hand in hand with economic development.

MITCHELL MOSS: If you want to make a good housing program, make an area safe, people want to live there.

If you want to have people come to visit, make the city safe, people will come there.

So, safety has been the underpinning of almost all of New York's renaissance.

HARI SREENIVASAN: Critics argue, however, that the police have trampled on the rights of tens of thousandsof young minority men because of the department's reliance on a tactic known as stop and frisk, a program recently ruled unconstitutional by a district court judge.

David Ourlicht was one of the plaintiffs in that case.

DAVID OURLICHT, Stop and Frisk plaintiff: I think that that creates distrust within the community,

because I think these communities, like, yes, we all want safe things, but I also don't want my son or my child or my uncle or my niece or my nephew or anybody in my -- or family and friends to have to be abused.

HARI SREENIVASAN: The mayor's stop and frisk policy, his missed record on education,

and his cuts to some poverty programs have fueled the perception that Bloomberg hasn't paid enough attention to the needs of poorer New Yorkers.

MICHAEL POWELL: It's the great challenge for New York is kind of how do you make room for and have this great vibrant metropolis that it's been for so many years,

while well over half your population is running very hard just to keep up, and, frankly, they aren't keeping up.

HARI SREENIVASAN: Another long-term legacy of the Bloomberg era will be the reimagined landscape, everything from the High Line that I'm standing on here, to the redevelopment of the Atlantic Yards in Brooklyn, or the creation of Brooklyn Bridge Park, both of which are part of that borough's renaissance and will be with the city for decades to come.

Under Bloomberg, New York has also added 400 miles of new bike lanes across the city and two new subway lines are being dug.

MITCHELL MOSS: Before, zoning was done a block or a parcel at a time.

Now it was done 20 blocks at a time. So, almost 20 percent of the whole city has been rezoned under Mike Bloomberg.

HARI SREENIVASAN: Bill de Blasio, who received the most votes in yesterday's mayoral primary, campaignedon a platform to address the inequality between rich and poor in New York.

What role any mayor can play in bridging that divide is unclear, but many believe it remains one of the great challenges for the city going forward.

GWEN IFILL: You know, Judy, we shouldn't be surprised that New York had a crazy election, that it went from someone being way ahead to Bill de Blasio coming out of nowhere, and incredible bad blood between de Blasio and Mike Bloomberg.

You saw his family there.

He raised a question about whether he was using his family, because he is married to a black woman and hasblack kids.

JUDY WOODRUFF: That's right.

The issue of the stop and frisk issue, which Hari just explained, became an issue that really had not beendiscussed to one that was on everyone's minds and, one could argue, helped determine the outcome.

GWEN IFILL: Only in New York.