The spectacular failure of the "defund the police" movement was educational in a few ways, big and small.
1) Messaging is important. This is a "No duh" statement to most, but you'd be surprised by how many people seem perplexed by the fact that a good idea has to have good packaging. "The slogan doesn't matter! It wins by the virtue of its rightness alone!" As Dr. Phil would say, "How's that working out for you?" And if you answer, "It's working out great!" just remember that this is specifically the reason why Biden doesn't get to have a domestic agenda, and why Democrats aren't allowed to take a crap in the morning unless Manchin and Sinema approve of it first.
The ideas contained within "Defund the police" are good. Unfortunately, the slogan itself can only make people not already on board with it imagine a hellscape in which Mad Max marauders have taken over the neighborhood and are beating, robbing and raping their loves ones with impunity. Messaging matters. Sorry, guys. Otherwise you're going to have to explain why marketing is a multibillion dollar industry, or why Fox News exists.
2) Crime matters to the American people. Another "Duh" comment, but you can't tackle head-on the fact that right wing pundits get this concept just fine and are weaponizing it handily. Democrats have to show they take it seriously just as much as Republicans. The problem is doing so in a way that doesn't devolve into the same old "tough on crime" tropes that make society worse. Which brings us to the most important point...
3) Police aren't to blame for all their abuses; we are. Before the 2020 election, the onus for my condemnation of law enforcement and the justice system in whole fell on the justice system. Traffic ticket quotas, unlawful search and seizure, civil asset forfeiture, qualified immunity, the strength of police unions in thwarting accountability, plea bargaining, mandatory minimums, legalized corruption as a result of the war on drugs...I blame police and the justice system. (And this isn't even getting into the things police and the courts themselves have no involvement in, such as the treatment of inmates and how they fit back into society once they exit the prison system, all of which are their own dumpster fires).
But in 2020, the public saw police beat peaceful protesters across the country and we still punished Democrats for wanting to hold them accountable anyway. This illustrates that all the abuses I listed above didn't come out of a vacuum. We put the politicians in power who create laws that make them possible. So if you don't like those abuses, just ask yourself if you're the one who voted for the guy who promised to be "tough on crime." If you did, then the problem is you.