A couple of weeks ago, I argued that Elizabeth Warren may have smart policies, but Bernie Sanders has mass politics. Yesterday, Warren demonstrated the difference in action: she announced that unlike Sanders she will be declining an invitation to appear on a televised Fox News town hall.

When Sanders participated in the network’s town hall event, I explained why that was a good idea. Fox News is the most-watched cable news network in the country, and a large percentage of its viewers have low incomes. Sanders’s campaign is centered around demands for ambitious redistributive reforms that will directly and materially improve life for all working-class people — some of whom, unfortunately, watch Fox News and currently vote for Republicans.

Sanders sees those viewers as part of the project of remaking society. Speaking directly to them about how the Right is pulling the wool over their eyes is therefore an important political task.

Sanders is familiar with basic socialist ideas: that the interests of workers are fundamentally opposed to the interest of capitalists, that workers have common cause across their differences, and that workers uniting en masse in pursuit of their common cause is the best way to exercise power, force concessions from elites, and make society more equal.

Following from these principles, Sanders sees it as his responsibility to speak to working-class people regardless of where they currently fall on the ideological spectrum. He went on Fox News not only because he wants to get these people to consider voting for him in the 2020 election, but also because he has a long-term vision for reshaping the political landscape. He wants to drain the Right’s reservoir of (mostly white) working-class support — which the Right doesn’t deserve, since it works tirelessly against the interests of working people, giving tax breaks to billionaires, destroying unions, and whittling down the welfare state.

Of course, Sanders thinks Fox News is an odious and corrosive enterprise — he openly says so, and he expressed disdain for Fox so many times during his town hall that the hosts verbally took offense. But as he put it, “To me it is important to distinguish Fox News from the many millions of people who watch Fox News. And I think it is important to talk to those people and say, ‘You know what, I know that many of you voted for Donald Trump, but he lied to you.’”

The rationale Warren has given for abstaining from a Fox News town hall follows a different logic than Sanders’s rationale for participating. It goes like this: Fox is a toxic force in our culture because it pits us against one another for profit (no argument here) and contributing to Fox’s profits by appearing on the network means contributing to Fox’s ability to continue sowing division. Therefore, Warren will take a principled stand against Fox’s politics by boycotting the network.

It’s possible that this is simply a tidy post-hoc justification, and Warren actually doesn’t want to go on Fox for immediate strategic reasons, perhaps worrying that she would be hit with difficult or unfair questions and would underperform. It’s also possible she sincerely believes that personally boycotting Fox News is a better strategy for beating the Right than appearing on it to argue her case to its viewers.

If we take her at her word, Warren’s rationale makes her appear as someone who views politics not primarily as a mass phenomenon, but as a series of top-level negotiations — between, for example, good policymakers and bad ones, or between good high-profile national politicians and bad multibillion-dollar news networks.

In Warren’s scenario, Fox News’s politics will be defeated by a few principled liberal politicians engaging in a media blackout. In Sanders’s, Fox News’s politics will be defeated when the Left convinces a significant portion of the Right’s working-class base that they’ve been duped, and that the pro-worker left best represents their political interests.

One of these is a mass-political scenario in which millions of ordinary people play the leading role. The other is a tug-of-war among powerful elites, a scenario from which the ordinary millions are conspicuously absent, or at least of negligible importance.

Even if Warren doesn’t really believe her own stated rationale, her abstention still demonstrates a myopia about mass politics that will not serve her well in either her campaign or her hypothetical presidency. Many of Warren’s best policy ideas involve taking on the power of the capitalist class directly. That can’t be accomplished by well-meaning progressive politicians alone; they need millions of people in motion to make it happen. This is the meaning of Bernie’s slogan “Not Me, Us.”

For those of us who prefer Sanders to Warren, this is the real sticking point: we think the power to change society rests with the working class itself, not with politicians who have its interests at heart. The major contest in society is between a handful of economic elites and everyone else who sells their labor for a wage in order to survive. Morally upstanding politicians are not the hero of the story. Working people are.

Politicians who understand this have a specific role to play: they have to use their campaigns and their offices as bully pulpits for a mass political perspective that unites working people against capitalists. And to do that, they must take every available opportunity to speak to every section of the working class about what they stand to gain from a Left agenda — and in many circumstances, what they have to lose by continuing to support the Right.

By refusing to go on Fox News, Warren has demonstrated that she doesn’t take this task as seriously as she ought to. As Sanders has plainly stated, the power of the capitalist class is so formidable that it will take a huge movement of millions of united workers to actually overcome it in reality. Warren’s policy ideas are frequently excellent, but without a fundamental orientation toward the very people who stand to benefit from them, they stand little chance of materializing.

Millions of people need to be persuaded that they deserve something better, that change is possible, and that they are the engine of that change. Demonstrated policy expertise won’t cut it, nor will principled stands against bad actors. What’s most important is speaking directly to working people on the biggest possible platform. Warren and Sanders may largely share a policy agenda, but in the end, only mass politics can get the goods.