There is no question that the Bernie Sanders presidential campaign has changed American politics. Just how radical that change will be is still being contested. Now that the Sanders campaign is nearing its end, organized labor, a major component of the Sanders coalition, will need to take stock of the forces mobilized throughout the campaign and figure out what to do next.

From the beginning of the campaign, it didn't take long for working-class supporters of Sanders to make their presence felt. They could be spotted before the first state had caucused.

"I went to Iowa five times. I focused on the Quad Cities by the Mississippi; these were manufacturing cities. The level of support there was almost universal," says Larry Cohen, former president of the Communication Workers of America and now part of the Sanders campaign.

While Sanders got plenty of attention for his appearance on Verizon picket lines during the recent strike there, Cohen points out that as far back as September 2015, Sanders visited striking workers at Penford Products while campaigning in Cedar Rapids, Iowa. While Sanders has long had support from labor, emphasizing these links has been important at a time when the labor movement seeks to rebuild itself after decades of decline. Some trade unionists even joke that America may have organized labor, but it does not have a labor movement. The Sanders campaign is presenting an opportunity to change that, though that path is not a straight line.

"We're in a place where we could create for ourselves something that is substantively different. It's not clear we are there yet," says Adolph Reed, a political science professor at the University of Pennsylvania, who was part of the group Labor For Bernie and campaigned extensively for free higher education.

The whole of organized labor certainly is not there yet. Though only seven unions endorsed Sanders at the national level, union members across the country were feeling the Bern. And that led to some interesting developments in the labor movement.

"Early on, the American Federation of Teacher and Machinists made top-down endorsements of Hillary. They incurred a significant blowback mostly on social media. You saw with the machinists and the teachers that their Facebook pages just blew up with angry membership responses," says Rand Wilson, a union staffer who was involved with Labor For Bernie. "We at Labor for Bernie amplified that. We encouraged people to speak out. We made sure that the news media was paying attention to the membership response because we wanted to send a message to some of the other unions."

This early blowback would have an impact on how other big players in organized labor would deal with endorsements. It was now difficult to move forward in the traditional top-down way of many unions.

"One effect that Bernie has had pertaining to the labor movement is that he has legitimated the idea that members should have something to say about their union's decisions in politics," says Jane Slaughter, retired labor journalist at Labor Notes and part of Labor For Bernie. "This time, people cared so passionately about Bernie that they were willing to make a fight in their unions either to get their unions to endorse Bernie or hold off endorsing."

The unexpected decision of one of the AFL-CIO's largest members, the International Brotherhood of Electrical Workers, to leave it up to their locals to make endorsements would have a major impact on labor support for Hillary Clinton until the primary was nearing the end.

"In terms of the AFL-CIO, they needed a two-thirds majority of their executive council (for an endorsement). The biggest factor there is how one of their biggest affiliates, the IBEW, made the unusual decision the let their locals decide and recommend. Thirty locals endorsed Bernie; none endorsed Hillary," says Wilson. "To get to two-thirds [AFL-CIO president Richard] Trumka really needed the IBEW. That's why they didn't make a move until after the California primary."

The lack of an AFL-CIO endorsement would rob Clinton of high-level coordination between her campaign and the largest unions in the country.

"Absent an AFL-CIO endorsement, the unions can't share lists. They can't coordinate their campaigns. That's pretty meaningful in terms of what happens on the ground," says Wilson. "When the federation makes an endorsement, we're all sharing our membership lists. All the unions in the AFL-CIO that stayed out or were endorsing Bernie were not sharing their membership lists. They couldn't have a coordinated campaign."

Those unions that did campaign for Sanders were now given the opportunity to boost their membership's organizing and political campaigning skills. The numbers were significant.

"This was a very politicizing campaign for our 185,000 members across the country, no question about it," says Fernando Losada of National Nurses United. "We canvassed in dozens of states, and for many of our members this kind of political work was new. We had tens of thousands registering people at work, thousands actively campaigning."

The kind of skills developed during a political campaign are also transferable within the labor movement.

"This was absolutely an opportunity to train our members. We know what you got to do in a political campaign, it's very similar to an organizing campaign. There's tons of list work, there's tons of phone calling, door knocking, canvassing just like in organizing," says Peter Knowlton, general president of the United Electrical, Radio, and Machine Workers of America.

The Sanders campaign demonstrated that rank-and-file union members were hungry for a new kind of labor movement, a new kind of politics, and were willing to get out there and make that happen. That is a hopeful sign for those who want a renewed left in the United States and the labor movement has a major role to play in that.

According to Reed, the Sanders campaign has shown just how important the labor movement is to building a left politics. "If you break with the fantasy of the spontaneous mass rising of the people or the related fantasy of some gimmick, some magical key that will unlock the door to change, realizing we can't use the corporate media, we have to recognize it will be a long protracted struggle to build the kind of movement we need. It's the labor movement that has the resources, the experience, the talent, and the connections that are essential to build such a movement."

Nor is Reed phased by the current size of the American labor movement. "I know people say that it's only nine percent of the workforce. And I say, compared to what? What else you got? That's nine percent of individual members, but those people have families, friends and social networks." He points out that the labor movement has a broad constituency. "It's the largest black political organization, and the largest Latino political organization, the largest women's organization, and probably the largest gay organization by membership in the country."

The next steps that the labor movement should take after the Democratic Convention are slowly coming into focus.

"In terms of specific strategy, that's still taking form. We had the People's Summit, and there was a lot of discussion, a lot of strategic questions raised. We were trying to foment a discussion among progressive forces that have been active in the field. We're now in the process of trying to synthesize that dialogue and experience and see which way forward," says Losada.

Though some criticized the People's Summit for not putting out a message of decisively breaking with the Democratic Party, others were impressed.

The UE have no illusions in the Democrats, and even endorsed Ralph Nader in 2000. However, Knowlton says of the People's Summit, "It was very well organized. They've done a very nice job of pulling all the disparate forces together, between the environmental movement, civil rights, Black Lives Matter, the Latino and immigration movement, and workers' rights movement. They've done a very good job helping to build that coalition."

Slaughter, however, warns against getting in too deep with the Democrats. "I don't think pouring your heart and soul in taking over the Democratic Party is going to work. It's not an empty vessel. It's got people at the top who don't want that to happen. Instead, people need to think about what are the local ways to act independently or work alongside some people that are in the Democratic Party and those who want to run outside of it."

Reed and several people from Labor For Bernie were once involved in trying to launch the Labor Party which lasted from 1996 to 2008. However, he believes that running as and supporting a Democrat is a tactical question. "The kind of leftoid argument that Sanders shouldn't have run as a Democrat and should now run as an independent, I just think is totally out to lunch. It comes in a couple of different flavors but each of them is either short-sighted or crazy."

But Slaughter also points out issues that the labor movement is going to have to tackle in the short term after the convention, before the issue of political parties is resolved. "First order of business will be stopping the lame-duck Congress from passing the TPP, which Obama will want very much to pass. Hillary won't stop this if she's the president-elect. The next thing, which was something that was not done after Obama was elected, was activism. The unions just dropped any kind of activism. I think a lot of people learned their lesson that simply can't be done. Even with a president you think is fantastic, you still have to keep the heat on."

From there, Slaughter argues that the left unions should follow Bob Master's proposals. "He proposes that the unions that endorsed Bernie form a coordinating committee and think about taking up some national campaigns. I think that would be absolutely an excellent outcome of this whole thing, if some unions constituted themselves as the left wing of the labor movement and said we're gonna keep the heat on in the streets."

In the wake of the Sanders campaign and significant victories like the Verizon strike, American labor is at a crossroads. It can retreat into its bureaucratic comfort zone and support whatever politicians the Democrats nominate, or it can take advantage of the groundswell radical campaigns and social movements to reassert its radical traditions that were stamped out after 1945. The months leading up to and after the nomination of the next president will tell us a lot about where it's planning to go.