Editor's note: Errol Louis is the host of "Inside City Hall," a nightly political show on NY1, a New York all-news channel. The opinions expressed in this commentary are solely those of the author.

(CNN) -- The tens of thousands of law enforcement officers who flocked to New York City for the funeral of slain police officer Rafael Ramos showed that civil rights demonstrators have achieved one of their central goals: What was once seen as an isolated string of local controversies about police-community relations is now a national debate about how to keep neighborhoods safe without abusing or alienating residents.

But watching the awesome display of police unity, the activists should be mindful of the old saying: Be careful what you wish for -- you just might get it.

The legion of blue uniforms the world saw streaming down Myrtle Avenue were far more than a group of grieving cops -- they also represent a vast, potent political force that is now beginning to respond strongly to national activists who claim that many local police departments are tainted by racial bias, brutality and a blue wall of silence.

Shocked into action by the assassination of Ramos and his partner, Wenjian Liu, cops in New York and elsewhere are proving that civil rights groups don't have a monopoly on the pageantry, slogans and public appeals of grass roots politics.

The new reality was on display at Ramos' funeral, as hundreds of officers pointedly turned their backs as New York City Mayor Bill de Blasio delivered a eulogy for the dead officer. The day before the funeral, a group of active and retired officers hired a plane to fly up and down the length of Manhattan for hours trailing a banner saying "De Blasio, Our Backs Have Turned to You."

The tension between de Blasio and the NYPD isn't the only sign that there are two sides to the national debate on policing. On the same day Ramos was buried, thousands of cops rallied in a downtown Cleveland demonstration called the Sea of Blue and in Houston and Atlantic City.

Last week, a group claiming 14,000 followers on Facebook organized a pro-police rally in New York City and squared off against activists protesting police brutality. Similar rallies have popped up in California, New Jersey, Iowa, Utah, Massachusetts, Tennessee, Washington, Arizona and other states.

The pro-police activists, taking a page from anti-brutality demonstrators, have made use of the slogan "Blue Lives Matter," a direct link to the national spread of protests and signs insisting that "Black Lives Matter."

The blue backlash should come as no surprise. It was always a political stretch to claim, as some demonstrators have, that thousands of local departments share the same problems of bias, racial profiling and overly aggressive policing.

The reality is far more complex. The horrific death of Eric Garner in the Staten Island area of New York City, caught on video, was ruled a homicide caused by chokeholds applied by police officers -- cops who still face internal disciplinary procedures that could cost them their jobs.

That's different from the much murkier circumstances in Ferguson, Missouri, where unreliable witnesses were allowed to give a grand jury wildly conflicting accounts of what happened in the minutes before an unarmed teenager, Michael Brown, was gunned down.

The facts are different in a third recent case, in which 12-year-old Tamir Rice was shot to death in a playground while playing with a toy gun. Tim Loehmann, the rookie who killed Tamir, had previously been found "distracted" and "weepy" during a firearms test; an instructor wrote that Loehmann "could not follow simple directions, could not communicate clear thoughts nor recollections, and his handgun performance was dismal" -- a damning record that Cleveland authorities never reviewed before hiring Loehmann.

These three horrific killings demand different solutions. Ferguson, a mostly-black town with an overwhelmingly white police force and political establishment, suffers from racial tensions that extend well beyond policing issues. That's a world away from New York City, where the police force, like the city itself, is mostly non-white.

And in Cleveland, the killing of Tamir came around the same time the federal Justice Department issued a report concluding, after a two-year investigation, that the Cleveland police department has a pattern of "unnecessary and excessive use of deadly force, including shootings and head strikes with impact weapons" and "the employment of poor and dangerous tactics that place officers in situations where avoidable force becomes inevitable."

If activists insist on arguing that these very different local allegations of excessive force form a common national problem, they should be ready for cops and their allies to respond in kind -- which will likely create more controversy and confusion, not less.

The National Law Enforcement Officers Memorial Fund lists 125 officers killed this year, under strikingly different circumstances. Consider what would happen if we considered them all part of the same phenomenon.

On the same day Ramos was laid to rest, a funeral was held in Florida for Officer Charles Kondek, a father of five who was responding to a noise complaint and was abruptly shot to death by a fugitive. And on the same day, a 24-year-old rookie named Tyler Stewart was shot to death while responding to a domestic violence call in Flagstaff, Arizona.

Should we see all those cases as connected? More importantly, do we really want all police thinking there's a realistic chance they could be assassinated by a madman without cause or warning, as officers Ramos and Liu were in New York, or shot to death on any routine call about a noise complaint or domestic violence?

That would be a formula for jumpy officers in constant fear for their lives, which is the very last thing any city or town needs.

A more reasonable way forward is to heed the advice of NYPD Commissioner William Bratton, whose emotional eulogy for Ramos included the observation that "We've all come to see only what we represent, instead of who we are. We don't see each other. The police, the people who are angry at the police, the people who support us but want us to be better, even a madman who assassinated two men because all he could see was two uniforms, even though they were so much more. We don't see each other."

We need more civil rights demonstrators willing to stop lumping all cops together as part of a national crisis, and more police who can find and fix the places where bias and bad policing taint their profession. That will be a tall order in a country where two big grass-roots movements appear to be on a collision course.

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