Washington (CNN) New York City Mayor Bill de Blasio on Sunday assailed former Mayor Michael Bloomberg's decision to apologize for "stop and frisk" on the verge of a possible 2020 run , casting the decision in an interview with CNN as politically craven and referring to it as a "death bed conversion."

De Blasio, who dropped out of the 2020 race earlier this year , said that Bloomberg had six years since the end of his tenure to re-think his support for "stop and frisk," but instead was notably dismissive of anyone who said he had been wrong on the policy.

"He had almost six full years to say it was wrong... we have had plenty of inflection points where he could have said, 'You know what, I was wrong,'" de Blasio said in a phone interview. "He has never cared to do that. And I think that says something about the veracity of this."

The policing approach, officially called "Stop, question and frisk," sparked a backlash from activists throughout Bloomberg's tenure as mayor because it disproportionately affected African American and Latino men. Police department figures showed that nearly nine out of 10 people "stopped and frisked" in 2011 were African American or Hispanic.

De Blasio ran for mayor in 2013, in part, on a platform to end Bloomberg's "stop and frisk" policy and has been a vocal critic of the kind of policing for years. A September Sienna College poll found just 33% of New York City voters say they have a favorable opinion of de Blasio with his unfavorable rating reaching 58%.

The unpopular mayor said that Bloomberg could have gotten away with his backtrack if he had done it a few years after he left office.

"But to wait six whole years and only when it is a matter of need, I think that raises eyebrows," he said. "This is a death bed conversion," he added, arguing that Bloomberg is only doing an about face because his previous position is wholly out of step with the Democratic electorate.

"We all appealed to him for years to reconsider and I think it is a statement on him that he was very dismissive," de Blasio said. "This was part of a pattern of being absolutely insensitive to the need to balance safety and fairness and being unwilling to listen to community voices."

De Blasio said people "may forgive" Bloomberg for his years of support for the policing policy, but "we will not forget."

"It was too big a mistake and too haughty a mistake to simply be brushed aside. It is at least as much about the fact that he didn't care to listen to communities of color and he didn't listen to reformers. That speaks volumes," de Blasio said. "This is a problem for him that people are not going to see it as consistent."

Earlier this month, Bloomberg's team filed paperwork to get on the Democratic primary ballot in Alabama and Arkansas. His spokesman Howard Wolfson had previously said if Bloomberg decided to launch a 2020 bid he would not run in the first four contests: Iowa, New Hampshire, Nevada and South Carolina.

African American Democratic voters play a crucial role in both the primary and general elections in the Palmetto State.