Columbus Day turned out to be an illuminating moment for those of us watching the man who is all but certain to be new York’s next mayor, William DeBlasio. He chose the holiday to waffle on the great Italian navigator, a hero to many Italian-Americans, with whom Mr. DeBlasio himself identifies ethnically, as well as in many Hispanic nations.

Mr. DeBlasio seeks to differentiate between Columbus the man and the Italian culture, and the miscast Columbus whose unexpected discoveries made a conqueror of a navigator. That Columbus behaved badly by modern — and some would argue, even 15th century — standards is not a issue anyone is disputing.

Mr. DeBlasio’s knocking of Columbus for going to work for the Spanish, implying that this was somehow a betrayal of his Italian roots, is a new twist, however. Does he know his own history?

The idea of an Italian nation-state is of recent vintage. There was no Italy in 1492, but a collection of city-states and regions each with a separate dialect, cuisine, and outlook on life. Columbus surely looked upon himself as Genovese, not as Italian. To finance such a bold journey as he proposed, he would need resources far greater than those to be found in his native city of Genoa.

This led Columbus to the Spanish monarchs, Ferdinand and Isabella, who financed his journeys. Holding him to contemporary standards of behavior is off the mark. What Columbus is celebrated for today is his vision, initiative, and courage.

That Mr. DeBlasio would join the politically correct critics is to me akin to Mayor Dinkins’ establishment of special offices to handle the Balkanized affairs of the city’s ethnic groups. Thus offices were established for Hispanic-American issues, African-American issues, Asian-American issues, and European-American issues. The failure of the Dinkins administration was exactly this kind of group-think, rather than promoting the individuality that each of us possesses.

It led to the Korean grocery boycott, the weak response to the anti-Jewish riot in Crown Heights, and ultimately Mr. Dinkins’ defeat after just one term.

On education, Mr. DeBlasio has homed in on attacking the one consistent success our city has enjoyed for 75 years, that of our specialized high schools. It is troublesome that the admissions to the schools, done by rigorous competitive examination, has not been successful in providing as diverse a student body as we might like to see.

The answer to this problem is, as I’ve long maintained, the promotion of gifted and talented education from the earliest grades. The answer is surely not watering down the standards. This would insult every child who has earned his or her spot in our specialized high schools through hard work and innate ability. The accomplishment of young people like Dante DeBlasio, the candidate’s now-famous son, a student who won admission to one of those great schools, Brooklyn Tech, would be demeaned and diminished by his father’s misguided policies.

Fortunately, these admissions policies are governed by the State of New York, through legislation known as the Hecht-Calandra Law, named for two great Bronx legislators with the courage and vision to stand up for high standards a generation ago. Standing as a bulwark against watering down standards is the State Senate, since Assembly Speaker Sheldon Silver has already sided with Mr. DeBlasio on this one.

It is these little issues that define the success or failure of government. That Mr. DeBlasio can be so wrong, so fast on some of them should give us all pause. Will a DeBlasio administration turn out to be a reprise of the failed Dinkins years, a return to a failed era in a time-machine fueled by political correctness? This is a time to remember that caution is a virtue.