The points of agreement between these two parties are numerous. Both point to a multitude of progressive positions Sanders has promoted: he wants to raise taxes on the rich, create green jobs, make it easier for workers to unionize, raise the minimum wage, he defends Social Security, calls for a single-payer health care system, and the list goes on.

Both the ISO and SAlt agree that Sanders’ campaign within the corporate-controlled Democratic Party is a mistake and have encouraged him to run as an independent. For the ISO this is a decisive mistake, and consequently, they refuse to endorse Sanders. But for SAlt, this is not a red line. Instead, SAlt argues Sanders’ campaign, even though conducted within the Democratic Party, has the potential to “mobilize hundreds of thousands against corporate politics,” and it is better to be in the campaign in order to more effectively influence followers of Sanders in the direction of independent political action. “By boldly intervening in the Sanders campaign – supporting its call for a determined fight against big business while arguing for independent politics,” SAlt argues, “we can most effectively advance the project of independent politics under the current circumstances.” In other words, Sanders followers can then be enticed to join truly independent movements, such as the fight for $15.

When Sanders loses the Democratic Party presidential nomination, SAlt will urge him to continue his run as an independent, even though Sanders has insisted he will instead endorse the Democratic Party primary winner.

Surely, Sanders’ decision to plant himself firmly within the Democratic Party and endorse whichever Democrat wins the primary should raise problems for any revolutionary. The Democratic Party is basically top-down, controlled by corporations, and pro-capitalist. When a revolutionary supports a Democratic Party candidate, it is like boarding a train that is headed in the opposite direction of one’s destination. Even though SAlt argues that Sanders can still be supported as a Democratic Party candidate, it is hard not to conclude that such a stance will sow more confusion than clarity among SAlt followers. Sanders has organized his campaign within a corporate, capitalist party and is running on a weak, progressive program. How can such a campaign represent principled, independent working-class politics?

But even if Sanders had chosen to spurn the Democrats and run as an independent, the question can still be raised: Should Sanders be supported by anti-capitalist socialists as an independent? And here the ISO has raised some points of caution.

Todd Cretien of the ISO, for example, notes that Sanders has operated closely with the Democratic Party by routinely caucusing with them; Sanders has supported the reactionary Democratic Party governor of Vermont; and he has supported U.S. government war efforts abroad. Moreover Sanders’ version of “socialism” is of the European social democratic variety, which has little to do with Marx’s definition of socialism. Social democracy accepts capitalism but insists on a strong safety net for the working class. And their acceptance of capitalism is crucial; it means that during an economic crisis, their first impulse is to support corporations, which are the mainstay of the economy. During the current economic crisis in Europe social democrats in one country after another have shamefully embraced severe austerity measures that punish the working class in order to strengthen the corporations.

Ashley Smith, also writing for the ISO, has argued that in many respects Sanders is indistinguishable from Democrats, given that Sanders has voted with them 98 percent of the time, has refused to support the fight for $15 except as a far distant goal, and has refused unambiguously to condemn racist police brutality. She quotes Howard Dean as declaring Sanders to be “basically a liberal Democrat.”

But Ashley Smith does leave a door open for supporting people like Sanders: “If Sanders had his heart set on national politics, he could have run for president like Ralph Nader as an independent, opposing both capitalist parties, the Democrats and Republicans.” Under this condition, Smith seems to imply it would be permissible to support Sanders with his progressive, anti-corporate agenda.”

Yet, the description of Nader’s campaign as “independent,” raises the question: Independent of what? Running independently of the Democrats and Republicans does not in and of itself amount to running a working-class independent campaign. There are more capitalist parties aside from the Democrats and Republicans, and the essential dividing line for revolutionaries is working class versus capitalist class. Like Sanders, Nader is not anti-capitalist; he wants to reform capitalism – remove its worst features and rope in the corporations – but not abolish it altogether. Surely, a candidates’ pro-capitalist position must present an insurmountable obstacle for revolutionaries who want to up-end society and create an entirely new, cooperative economic system.

Nader’s and Sanders’ pro-capitalism is not a trivial issue. Capitalism is above all an economic system that promotes diametrically opposed interests between workers and capitalists. Capitalists must compete against one another in order to survive, and to compete successfully they must maximize profits, which in turn requires keeping production costs, including labor costs, to a minimum. Stores like Walmart thrive on this strategy. Sanders might say he is for ordinary working people or for the “middle class,” but in so far as he embraces capitalism, he is also for corporations, because capitalism cannot operate smoothly without the smooth functioning of corporations, and hence, Sanders’ loyalties are at best divided. His distinguishing attribute is that he favors a tighter leash on corporations and a stronger safety net for the working class, which is mere reformism.

But capitalism is not simply an economic system – it creates an entire culture that invades almost every aspect of life. It is a top-down culture where those on the bottom are virtually powerless and those on the top issue orders. It atomizes people by forcing them to compete against one another rather than join together in the pursuit of the common good. This is the culture that one confronts at work, whether in the private or public sector, in schools where students must compete against one another for grades, and it even infuses the union movement. Union members are rarely encouraged to engage in significant decision-making within their union (with the exception of unions like the Chicago Teachers Union) and hence for the most part do not bother to vote in union elections. Similarly, when unions call for mass demonstrations, few of their members bother to show up.

Both the campaigns of Nader and Sanders adopt this top-down structure. Their programs are issued as proclamations from the top with little input from their supporters. And neither candidate makes an effort to forge solidarity with grassroots movements such as Black Lives Matter or the Fight for $15. Sanders won’t even return Nader’s phone calls.

Even more, as Marx and Engels insisted, the overthrow of capitalism will only be accomplished by the working class. “The emancipation of the working classes [of every country] must be conquered by the working classes themselves….” [Karl Marx: “Provisional Rules of the Association,” in The General Council of the First International, 1864-1866]. Hence, the goal of revolutionaries must be to consistently assist in the organization of the working class so that it is in a position to consciously act in its own self-interests independently of the interests of capitalists. Working people must come to the realization that they are members of an exploited class, that capitalism does not operate in their interests, and their only salvation lies in joining together in order to collectively create an entirely different economic system that actually operates in the interests of the majority. Capitalism will never be abolished by a minority of the population.

Neither Nader nor Sanders is dedicated to promoting the self-organization and self-liberation of the working class. Just the opposite: they reinforce the top-down culture of capitalism. They do not encourage working people to act collectively to defend their own interests, as is being done in the union movement, in Black Lives Matter, and in the fight for $15. Instead, they are prepared, if elected, to occasionally dispense favors for the working class, while leaving working people permanently atomized and powerless.

Similarly, Green Party candidates, such as Nader on occasion, represent equally flawed alternatives. Although the Green Party includes many members who, as individuals, consider themselves socialists, the Green Party itself is not socialist but capitalist. It calls for tighter controls on corporations, not for a collective and democratically controlled economy, despite Naomi Klein’s persuasive argument that saving the environment will require a confrontation with capitalism. The Green Party is not based on working class politics.

Grassroots movements such as the fight for $15, Black Lives Matter, and anti-war demonstrations represent united fronts. In other words, working people who might belong to different political tendencies can activate themselves and wage a united struggle over an issue of common agreement, where their willingness to join forces maximizes their strength. Such united-front movements have the capacity to become massive, as has happened in the recent past in Greece and Spain. These movements can then nurture the rise of new revolutionary working class political parties that represent the interests that these movements have ignited, which is what happened with the creation of Syriza in Greece and Podemos in Spain. These parties then have direct links to the mass movements.

It is not impossible for the anti-capitalist left to launch a principled, class-independent political campaign in the absence of truly massive working class movements, but the chances of missteps are multiplied in their absence. Campaigns such as Sanders’, Nader’s, and those of Green Party candidates unfortunately only serve to blur class lines and miss-educate revolutionaries about the most basic category in Marx’s revolutionary philosophy: the self-emancipation of the working class through class struggle.