Here’s a better question: How, we wonder, will the country ever get beyond its stunted discourse about racialized violence when people like Mr. Giuliani continue to try to change the subject? Those who remember Mr. Giuliani as the hectoring mayor of New York know what he has to offer any conversation on race and violence — not a lot. In case you’re unconvinced, here is what Mr. Giuliani on Sunday said he would tell a young son, if he were black: “Be very careful of those kids in the neighborhood and don’t get involved with them because, son, there’s a 99 percent chance they’re going to kill you, not the police.”

Mr. Giuliani’s garbled, fictional statistic echoes a common right-wing talking point about the prevalence of “black on black” violence in America. Homicide data do show that black victims are most often killed by black assailants. (They also reveal that whites tend to be killed by whites.) This observation does not speak to the matter of racist policing and police brutality. Killings of the police have, mercifully, been on the decline during the Obama presidency. But unwarranted shootings by police officers remain a persistent problem, ignored for generations, exploding only now into the wider public consciousness because of bystander videos that reveal the blood-red truth.

Unnerved by black anger, Americans like Mr. Giuliani cling to false equivalencies. They have, for example, defamed the Black Lives Matter movement as a “war on cops.” (Tell that to the protesters in Dallas who smiled for photos with officers who were protecting their march.)

The debate is full of such untruths and misdirections. There is the colossal Texas lie, the one that says a “good guy with a gun” can always stop a bad guy with a gun (in Dallas, where some marchers and bystanders were armed, it took a bomb). There is Mr. Giuliani’s ludicrous suggestion that black people don’t know they need to be careful around cops, or somehow are complicit in their brutalizing. Alton Sterling, in Baton Rouge, and Philando Castile, in a St. Paul suburb, were posing no threat when they were shot. (Far from being ignorant of the ways of the police, fearful black parents long ago learned to impart the advice that Mr. Castile’s mother, Valerie Castile, said she gave her son: “If you get stopped by the police, comply. Comply, comply, comply.”) Eric Garner, on Staten Island, was unarmed and outnumbered by the officers who swarmed and smothered him.

In 1999, when Mr. Giuliani was New York’s tough-on-crime mayor, Amadou Diallo reached for his wallet and was cut down in a hail of police bullets. Patrick Dorismond was minding his own business on a Manhattan street in 2000 when Mr. Giuliani’s undercover officers confronted him and shot him dead. In one of the disgraceful acts of his or any mayoralty, Mr. Giuliani smeared the victim’s reputation and released part of his juvenile police record, as if to suggest that he deserved to be murdered.