(CNN) Potential presidential candidate Michael Bloomberg said that he "can't stand up here and tell you every decision I have made as mayor was perfect" and that his main goal as mayor was "saving lives" in remarks to civil rights leaders at the National Action Network on Monday. The former New York mayor, however, did not directly mention the controversial policing policy known as "stop and frisk" that he supported to fight crime as mayor -- an issue that could impact his possible 2020 run for President.

Bloomberg, the former three-term mayor who is considering running for the Democratic nomination for President in 2020, looked to curb the city's high crime and murder rate during his 12 years in office by empowering city police to more easily detain and question people. The policing approach, officially called "Stop, question and frisk," sparked a backlash from activists throughout Bloomberg's tenure as mayor because it overwhelmingly impacted African-American and Latino men. Critics called the measure racist.

Bloomberg's support for the tactic will come under renewed scrutiny if he decides to run for president as a Democrat in 2020 and questions about his current views of the policy loom.

"I can't stand up here and tell you every decision I have made as mayor was perfect," Bloomberg said at the breakfast honoring Dr. Martin Luther King Jr. in his first major public remarks as several fellow Democrats have already entered the 2020 race. "I listened to concerns, and I tried to be responsive. But I can tell you that we were always guided by the goal, first and foremost in all cases, of saving lives of those who faced the greatest risk of gun violence, young men of color, and by cutting murders in half I am glad to say some 1,600 people are alive today who otherwise would not be and most are young men from black and Hispanic communities."

He added, "Thankfully, they were not killed simply for being at the wrong place at the wrong time. I can't tell you their names, but I can tell you all across America, there are still far too many people who aren't so lucky and still far too many politicians who don't give a damn about them. ... I am not going to accept that, and I hope you won't either."

Bloomberg's remarks to the group founded by the Rev. Al Sharpton did not focus on stop and frisk. Instead, Bloomberg discussed his work for Democratic causes, such as the impact climate change has on predominantly African-American neighborhoods and the need for equal education opportunities, but he made a point of discussing how he has worked through differences as a leader.

"While Reverend Sharpton and I disagree from time to time, even today, we certainly knew we could do it without being disagreeable," Bloomberg said, adding that he and Sharpton often talked during his 12 years as mayor because the civil rights icon "didn't hesitate to call me."

Although the civil rights leader was one of the loudest opponents of stop and frisk, he invited Bloomberg to speak at Monday's event.

"I marched on him -- his house -- on stop and frisk. Yet every Martin Luther King holiday, he would come to the House of Justice. He knew he'd be heckled, but he'd still come because he had a policy, unlike his predecessor Rudy Giuliani: He was going to deal with us, in the civil rights community in New York, even when we disagreed," Sharpton said in an interview with CNN about Bloomberg ahead of Monday's event. "That's the same position I'm taking with him in terms of inviting him Monday."

Critics "won" the stop-and-frisk fight in New York, said Sharpton, who now wants to hear how Bloomberg and other potential presidential candidates will help solve other problems. Former Vice President Joe Biden also spoke at the National Action Network event on Monday.

On the campaign trail, Bloomberg will likely try to defuse criticism by drawing on statistics and figures that speak to his track record as mayor of a city with a population of 8.4 million in 2013. In a statement to CNN before his Monday remarks, Bloomberg said his administration had cut crime while also reducing the number of people incarcerated and challenging the National Rifle Association.

Sharpton said prior to Monday's event he's eager to learn more about Bloomberg's solutions for climate change, which he said disproportionately affects communities of color.

Criminal justice became a flashpoint issue in 2016, with Hillary Clinton routinely coming under fire for her support of the 1994 crime bill spearheaded by her husband, then-President Bill Clinton, and her use of the term "super-predator" to describe gangs and people with "no conscience, no empathy."

Some Democratic strategists watching the 2020 field believe Clinton's record pales in comparison with Bloomberg's, making it unfathomable that he won't be dogged by similar -- if not more fervent -- questions than the 2016 nominee.

"There are people in this race who have extensive records when it comes to criminal justice, and in this primary they are going to have to own those records. It is not theoretical this time," said one top Democratic operative who works on criminal justice reform issues.

On Bloomberg in particular, the operative said that "there is no scenario where he will not get activist pressure, and very extreme activist pressure, because of his record."

According to the New York Civil Liberties Union, more than 5 million stop-and-frisk stops were made during Bloomberg's 12 years in office, with nearly 686,000 stops in 2011 being the high point during his tenure. Blacks and Latinos accounted for more than 50% of the stops in 70 out of 76 New York precincts and more than 90% in 32 precincts.

"Though they accounted for only 4.7 percent of the city's population, black and Latino males between the ages of 14 and 24 accounted for 41 percent of stops between 2003 and 2013," according to the group's report on stop and frisk . "Nearly 90 percent of young black and Latino men stopped were innocent."

In the first half of 2018, about 89% of the more than 5,000 stops that were recorded were of blacks and Latinos, according to data from the group, and more than 3,400 of those people stopped were deemed "totally innocent."

"New York City had 650 murders a year when I came into office, and the toll fell heaviest on black and Hispanic young men," Bloomberg said in a statement to CNN prior to his Monday speech. "We were determined to do everything possible to stop gun violence, both by taking guns off the street and by taking on the NRA -- when few other elected officials were willing to do that. We steadily cut murders and saved thousands of lives -- while also reducing the number of people who were incarcerated."

In May of 2012, after an outcry from advocacy groups and a high-profile class action lawsuit, the city's police department sent then-city council speaker Christine Quinn a letter, stating it was taking various steps to "increase public confidence" in stop procedures. The changes included an explicit ban on racial profiling and a requirement for senior officers to audit stop reports in their precincts.

Bloomberg visited Brooklyn's First Baptist Church of Brownsville in June 2012, acknowledging the backlash. There, Bloomberg told worshippers that the policy "should be mended, not ended."

"The history of the decline in police stops is misunderstood. As crime hit historic lows, and more than a year before any court ruling, I pledged to a Sunday congregation in Brooklyn and to all New Yorkers that 'we must and will do better,' by reforming police practices, while continuing to drive down crime. And that's exactly what we did -- on our own accord. We cut police stops by 94%, while continuing to reduce crime and incarceration. I've never stopped fighting the NRA and those who oppose common sense gun laws that would make our communities safer -- and I'm glad to say that across the country, we've been making a lot of progress," said Bloomberg in the statement to CNN before his speech.

Bloomberg has avoided publicly denouncing stop-question-and-frisk, stoking even more criticism from civil rights activists who say voters won't believe him even if he does walk back the policy.

"I don't think you can restore trust without acknowledging when you are wrong, and towards the end of his administration the stop-and-frisk activity was reduced, but at the same time, his administration fought tooth and nail to defend his stop-and-frisk policies," said Donna Lieberman, executive director of the New York Civil Liberties Union.

Ahead of Monday's event, Sharpton said Bloomberg will have to answer for "bad policy," but he stressed that all candidates come with "baggage" they'll have to explain. Sharpton, who said Bloomberg supported other policies that helped communities of color, told CNN he hasn't decided who he's going to endorse but won't rule out supporting Bloomberg.

Bloomberg has put his financial muscle behind issues he cares about, including climate change, gun safety, education and immigration. In recent years, the billionaire has spent at least $500 million of his own money to advance those issues, according to a Bloomberg spokesman. That amount includes backing the nonprofit Everytown for Gun Safety, which spent $30 million during the midterm election cycle, according to a spokesperson for the group.

Still, a Bloomberg campaign will continue to be criticized by activists who vow to make the stops an issue for him should he run.

"The only chance he has is that there is the rest of America that didn't actually come up in New York City at the time when Bloomberg was pushing these racist policing policies," said Jonathan Westin, the executive director of New York Communities for Change, which helped fight the police tactic. "But we will definitely remind America where he came from and what he did here in New York City."