Some will attribute Kristy Marmorato’s election as the first Republican to represent The Bronx in City Council in 40 years to selfish NIMBY-ism.

And there is no doubt her opposition to two subsidized- (a k a “affordable-”) housing developments in the northeast Bronx (District 13) were a key factor in her defeating incumbent Democrat Marjorie Velazquez — an outcome Rep. Ritchie Torres said would be a “national embarrassment” for Democrats.

Here’s what even a moderate Dem like Torres doesn’t understand: Kristy Marmorato is right about affordable housing.

New York City needs new and different types of housing; what it doesn’t need is more subsidized housing.

Commonsense Dems such as Torres need to understand why.

Housing advocates fail to acknowledge New York already has far more public and subsizied housing than any other US city: 180,000 units of public housing, 125,000 housing vouchers and nearly a million rent-regulated apartments.

Simply put, if subsidized housing can solve a housing “crisis,” New York would have solved ours long ago. 

Instead, all the above subsidies, along with newer versions such as that Mamorato opposed in The Bronx, help a favored few while distorting the overall housing market.

Income-restricted “affordable” units require households to qualify based on their income — but they can stay as long as they want even if their incomes go up.

Nor is there any time limit on public housing — where some 20% of tenants have lived for 40 years or more.

Similarly, rent-stabilized units turn over far more slowly than unregulated apartments.

If you get a sweet deal in New York, you hang onto it — even if it has more bedrooms than you need as you age, even if you have a summer home in the Hamptons.

Ambitious newcomers give up on finding a place in the city they can afford or must live in partitioned units with adult roommates.

What’s more, middle-class neighborhoods like Throggs Neck and Morris Park, where Marmorato triumphed, rightly understand subsidized tenants as a quality-of-life concern.

Of course, not all subsidized tenants are drug dealers or shoplifters.

But middle-class homeowners know those granted the gift of affordable housing have not made the same life choices and sacrifices — scrimping and saving for down payments — they have.

The sad fact is affordable projects look great when the ribbons are cut but deteriorate over time. Homeowners have seen it elsewhere.

This is an old story in New York the left has long failed to acknowledge.

As long ago as 1972, middle-class Forest Hills stridently opposed a high-rise subsidized project — and dogged and undermined John Lindsay’s failed presidential campaign because of it.

The controversy launched the career of an obscure Queens attorney, Mario Cuomo, who forged a compromise — reducing the project’s scale — but acknowledged, in his book “Forest Hills Diary,” opponents had a good point.

He presciently noted African-American homeowners were as likely as whites to oppose the projects.

They, like middle-class Bronx residents, moved up and out of lower-income neighborhoods and don’t want what they’ve left behind to follow them.

Subsidized housing opponents were “sincere and reasonable” when they argued that “any substantial influx of the poor carries the danger of crime and decay,” Cuomo wrote. “Those blacks” in Queens’ Hollis “fortunate to have homes of their own . . . unhesitatingly said they would not want the project in their neighborhood.”

He would not be surprised at what one Bronx Stop Upzoning member told NY1.

“We are struggling to pay our mortgage, and then they do this,” Rosaura Rodriquez said, objecting to the idea those opposed to the project are racist. “Over here we are all mixed, they are black, Spanish, Indian,” she said. “I feel sad because why they doing this, I don’t understand.”

That’s how a Republican can win in a district in which only 14% of voters are members of her party.

In other words, Kristy Marmorato’s 1,000-vote victory should be a lesson to Democrats across the country.

Failing to understand the concerns of middle-class voters — including blacks and Latinos — is a recipe for defeat.