The New York mayor’s race is barreling toward November. The once-crowded primary bus now has just one Democrat and one Republican, Bill de Blasio and Joseph Lhota, grappling for the wheel. (An independent, Adolfo Carrión Jr., is in there, but a few rows back.)

A contested election for a soon-to-be vacant office should mean a bracing battle between nonincumbents with clearly contrasting visions for the city going forward. But all everybody’s talking about is the past.

The race is awash in anti-nostalgia, much of it coming from the critics of Mr. de Blasio, who see his distinctly liberal campaign, with its promise of taxing the rich to close Dickensian class divides, as a throwback to the worst of times, the 1970s and ’80s, when a string of Democratic mayors presided over a “crime-ridden, crumbling and alienated metropolis,” as The New York Post despondently put it. The conservatives’ theme is that the city is stable and safe today only because of the strong hands of the Republican Rudolph Giuliani and the on-and-off Republican Michael Bloomberg, and that disaster is right around the corner in the form of squeegee men and vagrants, crack houses and near-bankruptcy.

This is nonsense, but it keeps coming up, and Mr. Bloomberg hasn’t been helping. Though he hasn’t endorsed a candidate, he has summoned that somewhat distant past of rampant crime and bitter race relations to attack Mr. de Blasio. He made and retracted, through a spokesman, a bizarre remark accusing Mr. de Blasio of running a “racist” campaign featuring his biracial family. He went apocalyptic in predicting anarchy if the next mayor forbids the Police Department to unconstitutionally stop-and-frisk innocent young black and Hispanic men by the thousands, as Mr. de Blasio has vowed to do.