Not so long ago in New York, teacher evaluations were the hottest button in public education. Gov. Cuomo was the chief proponent, arguing that up to 50 percent of teachers’ grades should be based on how well their students did on standardized tests.

These days, nobody, including Cuomo, even talks about teacher evaluations. Instead, thanks largely to Mayor de Blasio and his chancellor, Richard Carranza, racial quotas are the new hottest button.

As Carranza recently declared at Al Sharpton’s headquarters, “We’re not about improving the system. We’re about changing the system.”

The implications involved in this change of focus are enormous. Most important, the results of imposing a radical race-based social-justice experiment on schools could be tragic for thousands of children and their families.

The concept of linking teacher evaluations to student performance was a reform idea of its time pushed by then-Mayor Bloomberg and others who were searching for ways to measure the impact of good and bad teachers. It was aimed primarily at improving failing schools in the poorest neighborhoods because many were dumping grounds for the worst teachers.

A linkage between teacher quality and student outcome is such a no-brainer that it quickly went mainstream. President Barack Obama’s administration supported it, despite the fact that he and other Democrats counted on the political backing of teacher unions.

The unions fought back. Constant in their commitment to protect every teacher from firing, including those facing serious criminal charges, they wanted to keep the lopsided system where virtually every teacher was rated “acceptable” even when as few as 15 percent of students were reading at grade level.

The unions succeeded when the entire political establishment of both parties surrendered. Teacher evaluations and student performance are now effectively seen as separate issues in New York.

The one thing that hasn’t changed is the student performance gap between racial and ethnic groups. A report last year from the city’s Independent Budget Office that followed 71,000 students starting in 2008 found that black and Latino students started third grade behind in math and reading comprehension, and the gap grew by the time they reached eighth grade.

And the dismal results released last week from state tests showed a similar pattern, with Latino and black students combined averaging 35 percent in English proficiency and 28 percent in math in grades 3 through 8. Asians and whites together averaged about 67 percent in English and 67 percent in math.

In short, little has changed — except de Blasio and Carranza are giving up on helping failing students and fixing failing schools in favor of blaming everything on racism, including test results. It certainly makes their jobs easier and helps them with their progressive pals.

It is also cruel to both good and bad students. Depending on the program, from one-quarter to one-half of the seats at some highly ranked schools will be reserved for failing students.

That means some good students will be denied the best schools. It also means students who are the least prepared will be thrust into the best schools.

Race, ethnicity and lotteries will replace merit in many cases.

Those failing students who get plunked into Stuyvesant or Bronx Science high schools will have little chance of succeeding because they are simply too far behind to catch up to their classmates.

While there will be some exceptions, most of those students are likely to fail.

There is, of course, another option: charters. Most specifically, Success Academies, which again posted extraordinary scores in the latest state exams.

With the city averaging 46.7 percent proficiency in English and 42.7 percent in math, Success students scored 91 percent in English and 98 percent in math.

About 93 percent of those students are nonwhite, proving that “children from all backgrounds can achieve exceptional results when given access to great schools.”

That’s how Eva Moskowitz described the results. She’s the CEO and founder of Success Academies, which now operates 47 schools with 17,000 students, and should be the chancellor.

Year in, year out, her results prove that the slow start of at-risk students can be overcome and the racial and ethnic achievement gaps can be erased.

She is also proving that de Blasio and Carranza are headed in the wrong direction, one that will be a dead end for education. Nonetheless, they will go on with their racial bean counting because, in an upside-down world, it’s a good career move for them.

Parents and children are out of luck.

Facts won’t alter Dems’ Kave-nope

Reader Jamie Gelfand asks the right question about the Brett Kavanaugh disgrace, writing: “If Christine Blasey Ford held a news conference tomorrow and said she made everything up and apologized for dragging Kavanagh through the mud, would even one Democrat change his vote?”

The question answers itself because the Dems keep moving the goalposts. When one line of attack fails, they come up with another. The only consistency is their determination to keep Kavanaugh off the Supreme Court.

Recall that some of the party’s initial talking-point objections described his judicial rulings as “extreme” and “out of the mainstream.”

They are neither, which is why the Dems moved on, as a last gasp, to allegations of sexual misconduct. Ford would never have been heard from if the “out of the mainstream” tag had gained traction.

And now that the sexual-misconduct allegations are proving to be riddled with holes, along comes charges that Kavanaugh is a problem drinker — or at least was in high school and college.

That’s not likely to work either, so already, we see the next line of attack taking shape. This one is that Kavanaugh got too mad and too partisan when he was falsely accused of gang rape.

No, we can’t have that in Washington, especially from Republicans. Only Democrats are allowed to fight to win.

That used to be true, in the BT era.

Before Trump. Now it’s a fair fight.

Yeah, right, MTA fix will be cheap & E-ZZ

It’s generally a cause for hope anytime government promises to save money. But a fishy smell about a vow from the MTA keeps hope grounded.

For 50 years, signs on the Verrazano Narrows Bridge have been misspelled because they lack a second “z.” There are 96 signs with the error, and in June the MTA estimated it would cost $350,000 to fix them.

Now it says the cost will be between $200,000 and $250,000, and Gov. Cuomo signed a bill to make the changes.

This sounds like election-year math, meaning too good to be true. Watch your wallets, taxpayers.

Oh, what claptrap!

From The Mirror, a British tabloid:

“Clapping has been banned at a leading university’s students’ union ‘to avoid triggering anxiety.’

“The University of Manchester Students’ Union passed the resolution to ban clapping at student union events.”

So then it’s not true there will always be an England.