(CNN) Critics said it wouldn't last. It was a blip on the radar of protest movements. It would fade away like Occupy Wall Street. With no clear structure and no strong leader, some said, it was bound to fail, especially when the infighting began. But still it rises -- and polarizes.

The Black Lives Matter movement has pushed itself into the national conversation again and again. It seems anyone can join them and anyone can claim to be a part of the movement, simply by creating a Facebook page or using a hashtag.

Still, it is praised as much as it is criticized. While there is no way to know exactly how large the movement has become, the organization has branched out with chapters in 31 cities and held rallies, boycotts and other actions across the United States, according to one of the co-founders.

For a group that started with a hashtag in 2012 after the shooting death of Trayvon Martin in Florida, it has grown into a social juggernaut. It has changed the way people talk about police brutality and inequality.

"Because of social media we reach people in the smallest corners of America. We are plucking at a cord that has not been plucked forever," Patrisse Marie Cullors-Brignac, one of the co-founders of Black Lives Matter says. "There is a network and a hashtag to gather around. It is powerful to be in alignment with our own people."

You can try, but it is hard to avoid the conversation about Black Lives Matter anymore. And that's exactly the point.

And part of that means really figuring out what the movement is about, longer-term; where leaders think they can do more than But the group is also trying to find its footing to make much more change.And part of that means really figuring out what the movement is about, longer-term; where leaders think they can do more than demonstrate and disrupt society and "shut sh*t down," as they often chant. They say it is about much more than each individual death of an African-American man or woman, it is about what it means to be black in America.

And that means learning how to make political change to address the frustrations of the African-American community. The movement wants a civil rights movement-type of change that shakes up politics and breaks the cycle of violence and silence.

To do that, it also must confront itself, its leadership and how it plans to operate. The group does not have one prominent leader, and that is by design.

"We don't have a one strong leader model. You can't kill the movement by killing the leader because there are many," Cullors-Brignac says. "But decentralization does not mean disorganization. We are highly organized."

Still there are those who have emerged as social media leaders, judging by their mass followings.

DeRay Mckesson is front and center, with 268,000 Twitter followers and counting. He drives conversation. He is poetic and polarizing all at once. He's been called everything from the new Martin Luther King Jr. to a devil intent on dividing America, depending on who is responding to him.

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Mckesson has been protesting in some form since the August 2014 police killing of Michael Brown in Ferguson, Missouri , which was eventually deemed justified by both a grand jury and a Department of Justice investigation. He is never absent from Twitter, where he skewers police accused in killings or brutality. He attacks police department tactics and the media, and his prominence keeps growing among those who hate him and those who support him.

While he is vociferous at times, he knows that the movement is bigger than any single person, and he wants to keep it that way.

"I think it's a movement of many people doing important work and leading in different ways. We've only begun to see the power and impact of that type of model," he said.

Protesting politicians, and maybe their allies

In the past 15 months, the movement has gone from local outrage in Ferguson to a tidal wave of awakening across the nation.

"We brought more people into the conversation, and they realized the problem is much closer to them than they think," Mckesson says.

But the group's tactics have come under intense scrutiny, sometimes by the very people it is supporting or who have supported it.

Some critics blame Black Lives Matter for worsening race relations in America, pointing to polls that show Americans think race relations are worse in recent years . But Black Lives Matter activists say just because they have pointed out racism in America, doesn't mean the group is to blame.

The group is also known to take over at political rallies of the very people who could be allies in their fight.

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When Black Lives Matter protesters interrupted Bernie Sanders at a campaign rally in Seattle in August, shouting their way onstage and later causing the Democratic presidential candidate to leave the event, some members distanced themselves, saying that didn't represent their agenda. But with the way the group has positioned itself, anyone with similar goals can consider themselves part of the group and movement.

Sanders' fellow Democratic candidate Hillary Clinton was next, later that month. But this time, they wanted to make sure she heard them. So they pushed to get close and have a personal conversation about paying more attention to the group's goals.

Republican presidential candidate Donald Trump hasn't escaped their ire, but he did manage to talk over them partly because some of his supporters pushed out one of the protesters during a speech in Alabama.

But the focus also had to be on real areas they could change now with leaders currently in power. At an October town hall meeting in south Los Angeles, Mayor Eric Garcetti showed up intending to listen and respond to the community to restore a frayed relationship. What he encountered was Black Lives Matter activists who stood up and turned their backs on him.

"The mayor has neglected, disrespected and abused the black community for far too long," said Melina Abdullah, a Black Lives Matter organizer and professor of African studies, grabbing everyone's attention.

While the crowd may have agreed with her, some were frustrated that members of the group had sideswiped their chance to have a serious conversation with the mayor.

"You have the subgroup trying to take over the town hall. Whatever they were talking about is not my reality," Daryle Shumake, a 45-year-old black health care worker, told the Los Angeles Times that night.

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In Minneapolis, protesters occupied the police department to demand that video be released of the police shooting of 24-year-old Jamar Clark. The officers involved in the death are on administrative leave pending state and federal investigations.

Black Lives Matters members continue to protest. Clark's family has been thankful for the activists' support but also frustrated at times with their tactics. Family members repeatedly appealed for peace, and respect for property, saying there's a fine line between protesting a cause and hurting the community.

Later, the Black Lives Matter movement was the target of a shooting outside the police department and the family again urged them to leave, this time for the group's own safety.

"Disagreements about tactics are totally normal. We have differing opinions. This happened during the 60s in the days of Martin Luther King, and the Black Panther movement," Cullors-Brignac says. "It is just that our disagreements are often displayed to the public in real time on social media."

She openly worries that the infighting can be destructive, but it shouldn't take away from the work that needs to be done.

Confronting violence and their path ahead

The Black Lives Matter movement is making a concerted effort not to encourage violence. It responds fiercely when accused of committing violent acts during protests. But this comes with the territory with a loosely formed group. When you organize or encourage protests and encourage all to get involved, then the group itself and the movement bear the brunt of the blame if some become violent or destructive, as was the case in Ferguson and Baltimore.

So, in Minneapolis, the activists took a different tack when they learned of a potential plot by white supremacists to incite violence to tarnish the movement. They told group members to make sure their faces could be seen, so fingers couldn't be pointed at them.

When a male walking around the crowd was asked to remove his mask and refused, the group questioned why he was there. When he said he was just checking things out, they grabbed him by the arm and escorted him out.

"Not today. You are not welcome to create chaos here. No sir," they said.

Again, some praised the group's actions, while others condemned them. They were trying to police themselves, but also removed someone from a public street.

Police later discovered Molotov cocktails not far from the protest site, though they never figured out who was responsible.

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The threats against the group itself are now fast and furious. Most are online. But some are in person. In Minneapolis, five demonstrators were shot. Police arrested three suspects, all of them white, after a confrontation between protesters and the men.

Despite the bumps, the hurdles and the accusations, the movement continues and grows across the country. The question is, what is the group's plan for the future and will it have an impact on policy, or will it just continue to make its presence known by protesting?

"In the beginning that was about awareness and recognition, helping bring attention to an issue," Mckesson said.

He and Samuel Sinyangwe, Britanny Packnett and Johnetta Elzie came out with a policy of sorts -- or at least a clear and concise list of principles for policy change. They called it Campaign Zero, and they map out policy issues and have honed in on areas in which they think they can bring about real change: police contracts and misconduct records; investigations of police; community representation; "militarization" of police; use of body cameras.

Mckesson says the key to the group's future is to start getting involved in hyper-local politics not just national races. Taking to the streets will always be a part of the movement, but taking over as policy-makers could change things forever.

"What does it mean when protesters become city council members, mayors, school board members?" Mckesson asked. "How will that factor into the next phase? How will we grow and change? The movement has matured, for lack of a better word, but it has to be multifaceted."