The intentionally cross-eyed left-wing notion that cultural diversity is America’s No. 1 value is the nonsensical grandson of the equally ignorantly conceived concept of affirmative action for college admissions, dating back to the 1960s.

A child in 1964 could have predicted the staggering failure of affirmative action.

This explains why leftists, 53 years on, still blindly promote it – as if they believed in it.

Last Friday in The Wall Street Journal, a prominent liberal, attorney-author Steve Cohen, and a noted conservative, John Katzman, founder of the Princeton Review, collaborated on an essay headlined “Let’s Agree: Racial Affirmative Action Failed.”

Although racism across America largely has disappeared today, it flared brightly in the ‘60s.

At a glance – but no more – affirmative action appeared a potential antidote.

However, as any rookie teacher with four minutes of experience will attest, you cannot stock your class with, say, 30 percent of grossly undereducated, undermotivated students and expect to promote them.

Affirmative action college graduates have been a punch line for years.

The number of black and Hispanic failures and dropouts on major affirmative action campuses makes the 405 at rush hour look wide open.

Even The New York Times, one of our country’s most prejudiced newspapers, has confessed that blacks and Hispanics have lost ground, gone backward in affirmative action since the early 1990s.

What ever happened to the antiquated value of measuring a boy or girl’s qualifications by his and her grades? How quaint.

Instead of surrendering to the diversity Nazis, colleges should recruit students who can count from 1 to 10 without cue cards.

Messrs. Katzman and Cohen end thoughtfully, cymbals clashing:

“Rather than continue to pretend that college admission is one big academic meritocracy, let’s be more candid about the complex and idiosyncratic needs of each school.

“Let’s explicitly reward students who have overcome disadvantaged financial beginnings, but not give one race an advantage over another. This is where we begin to create better outcomes and build a fairer, healthier system.”