I first met Bernie Sanders in the late 1980s. He was contemplating a run for Congress and had chosen to take time to study and teach at Harvard's Kennedy School of Government. We went out to lunch one afternoon.

Sanders was already a legend. An avowed socialist who had served as mayor of Burlington, Vermont, he struck me as someone who was quite thoughtful and prepared to listen to views other than his own. We chatted about a matter that has preoccupied me for much of the last thirty years: How to build a national electoral project that is truly progressive and also focused on the fight for power.

Sanders went on to win election to Congress and, ultimately, the U.S. Senate. He has been outspoken on virtually every issue that matters to working people and is unapologetic in his critique of capitalism. At the same time, he works to build unity among progressives rather than simply staking out his claim and expecting people to rally to his flag.

I don't live in Vermont, but without question, Bernie Sanders is my Senator.

For the last few months, the word on the street has been that Sanders is contemplating a run for the Presidency. Sanders has hinted at the possibility but has not confirmed or denied that he may take the plunge.

Excitement around a possible Sanders run is palpable. After more than one term of the complicated, neoliberal Presidency of Barack Obama -- combined with the relentless assaults by the political right on all that for more than sixty years appeared sacred -- there is a deep and clear desire among many for a different direction.

Yet a Sanders run brings its own complications.

One issue is whether Sanders should run as a Democrat or as an independent.

There are many progressives and leftists who will automatically suggest, out of disgust with the Democrats, that Sanders should make a "pure" run as an independent. Yet this raises an even more fundamental question: Why should Sanders run at all?

It only makes sense to run for the Presidency of the United States -- as a progressive or leftist -- if the person is both running to win and running as part of a broader electoral project. A run just to "show the colors" or make a statement is a waste of time. Running for President is both too expensive and time-consuming for that.

On the other hand, if the candidate has a real mass base, is building a broad progressive front around a clear, transformational program, and sees the candidacy as one step in a multitiered process, then it might be worth going for it.

But in suggesting this, I do so with qualifiers. Too many candidates who suggested that they were interested in building a grassroots movement that would transcend their campaigns only to see such candidates close up shop afterwards. A Sanders run as part of a longer-term effort at movement-building and energizing a progressive front only makes sense if there is a demonstrable commitment by the candidate to do the right thing after the election.

Let's take an example of what not to do. After Obama's successful 2008 run, there were many people who assumed he was going to keep his campaign organization together as a sort of independent force. But Obama moved it into the Democratic Party instead.

Then there was the choice that Jesse Jackson made in March 1989 when, following the 1988 elections, he completely reorganized the National Rainbow Coalition into an organization that he totally controlled rather than the mass democratic organization that many of its members had thought that they were building.

If a run makes sense, and I think Sanders might be the candidate who would turn his campaign into something lasting, the question is how to do it. I believe that Sanders needs to make a strategic decision to run within the Democratic primary system for the nomination. Despite the discontent with the electoral system among so many people in the United States of America, it is not likely that an independent candidacy at this moment can win. Should the Republican Party fracture, which is a real possibility over the next few years, all bets would be off. But as long as the Republicans stand firm as a hard, rightwing party, it is unlikely that at the national level an independent candidacy can win.

Quite explicitly, I am suggesting that winning must be a major objective of the campaign. The campaign needs to be organized in such a way that it aims to build an electoral coalition that is interested in gaining power, is committed to winning, and has a plan for governing.

Contrary to the contention of some of my friends on the left, there is no contradiction between running as a socialist and running as a Democrat -- with the real intention of taking office. Former Massachusetts state representative and two-time mayoral candidate Mel King was an independent socialist, yet ran for state office as a Democrat. Former Congressman Ron Dellums of California was also a socialist and a Democrat. Sanders could run as a Democrat yet be very clear and open about his socialist politics. Such a candidacy would send a bolt of lightning throughout the Democratic Party and change the discourse within it. An independent candidacy would not have anywhere near that impact.

A Sanders candidacy would need to also take on race. We live in a moment that is reminiscent of the period of the Southern coups in the late-nineteenth and early twentieth centuries when white supremacists usurped the franchise from African Americans and poor whites, and when Chicanos (in the Southwest) were treated to de facto segregation and voter exclusion. The political right, fearing the future, is moving to exclude millions of voters and ensure the ongoing supremacy of a quite xenophobic Tea Party-esque Republican Party. This is being orchestrated through the brilliant usage of racial symbols, all at a time when people of color have been suffering from the worst effects of the transformation of U.S. capitalism.

For Sanders to run and to make a real difference, he will need to tap into the African American, Latino, and Asian electorate and inspire them with a vision. This has to be far more than a "rising tide lifts all boats," but must acknowledge race and class as integrally connected. Sanders would need to speak out on the anti-immigrant hysteria of our times, as well as address the manner in which so many workers, particularly workers of color, are being rendered redundant in today's economy.

He would also need to be a candidate who denounces the misogyny that has pervaded U.S. politics. This is more than the question of abortion. It really goes to women's control over their own bodies, expectations of women in today's economy, who is to blame -- and not to blame -- for the declining living standard of male workers, and basic issues of equality.

I have no worry that Sanders will speak out on behalf of workers. Yet doing so will be insufficient for a campaign to gain traction. Sanders would need to be a spokesperson for a different path, one that addresses not only the issues mentioned above, but also a non-imperial foreign policy and an environmental policy that brings us back from the cliff of climate change. His voice would need to be the voice of the future -- the voice of the progressive bloc that seems to be assembling to prevent a dystopian future.

A primary challenge is worth it, even if he just pushes the victor to the left.

The last thing we need is another symbolic candidacy that, while touching our hearts and minds, brings us no closer to clobbering the political right and winning power for the dispossessed and the disengaged.

It can be done.

Bill Fletcher Jr. is a columnist for The Progressive. He is also a senior scholar with the Institute for Policy Studies, the immediate past president of TransAfrica Forum, and the author of "'They're Bankrupting Us'--And Twenty Other Myths about Unions." Follow him on Facebook and at www.billfletcherjr.com.