Betsy DeVos’s Senate confirmation hearings have offered a bright light in a dark time. The highlight reels posted to social media show Democratic senators revealing the billionaire’s ignorance on everything from pedagogical debates and student loans to federal law and the frequency of bear attacks.

These questions have not only been entertaining but also revealing. In the various attacks they’ve launched at the education secretary nominee — who does not believe in public education — the fault line between centrist and lefter-leaning Democrats has become even more apparent. In it, we can discern two different strategies of political battle for the next few years: the continued reliance on technocratic critiques versus resurgent class warfare.

Al Franken has served on the Senate’s education committee since 2009 and, to his credit, has spent those eight years studying important debates in education. He asked DeVos about one of these debates: “I would like your views on the relative advantage of measuring proficiency or measuring growth.”

For those readers who, like DeVos, have no idea what Franken means, it comes down to whether we measure students against each other (proficiency) or against themselves (growth). In a proficiency model, students are tested to see if they rise above, meet, or fall below a line set typically by the state. A growth model, in contrast, measures how much a student’s knowledge or ability in a subject area has improved over the course.

DeVos fumbled the question badly, clearly having no idea what Franken was talking about. The senator then explained the difference and laid his cards on the table: he advocates the growth model and is surprised that DeVos is wholly unfamiliar with the debate.

Within minutes, he reversed himself: he’s actually “not that surprised” that she didn’t have a good answer. Franken designed the question to humiliate DeVos, to demonstrate his superior knowledge in a field that she seems to believe she’s qualified to lead.

Franken isn’t wrong to question DeVos’s qualifications for the job. It’s baffling that we might have an education secretary who seems to have given more thought to conversion therapy than to basic questions about assessment, which has become a major battleground in public education.

But having an answer — or even an answer Franken liked — wouldn’t guarantee that DeVos would do a good job as education secretary. While measuring achievement has become a central debate in pedagogy, choosing a growth model over the proficiency model won’t do much to improve public education across the country.

The real problem with assessment isn’t how it’s done, it’s that it’s now tied to a host of non-educational issues like teacher retention and promotion and school funding. Testing has become such a site of dispute because school districts now use test scores to decide which teachers get fired and which schools get shut down.

We shouldn’t be that mad at Franken. His question does precisely what it’s intended to do, which is demonstrate that Trump’s pick for secretary of education knows next to nothing about education. And we should object to anyone as ignorant — and craven and doctrinaire — as Betsy DeVos holding the position. But Franken’s line of questioning won’t lead us any closer to fixing the United States’s educational problems.

In fact, questions like it tend to distract from what’s really at stake in these confirmation hearings. Admittedly, one thing that unites all of Trump’s cabinet nominations is that they are unqualified and don’t understand the departments they are being asked to run.

More damningly, however, and more politically useful as a line of opposition from the Left, they agree on an agenda of intense privatization and a whole host of policies that expand inequality and increase the power of capital — an agenda that establishment Democrats have been more than happy to comply with.

Luckily, when it was Bernie Sanders’s turn to question DeVos, he brought the hearing back to what really matters in education: funding. He asks her to commit to working with him to make public higher education free for all Americans. DeVos calls the idea “really interesting,” but reminds Sanders that “nothing in life is truly free. Someone’s going to pay for it.”

This was a perfect setup for Sanders:

Yes, you’re right. Someone will pay for it . . . Right now, we have proposals to substantially lower tax breaks for billionaires in this country while at the same time poor kids can’t afford to go to college. Do you think that’s fair?

Sanders’s question that sits right at the heart of any debate over education. While DeVos continues to promise to provide “opportunity” to every American, she is unwilling to recognize that without free higher education, those opportunities are simply unavailable to a large section of the American population, especially students of color. It won’t matter to these students if their high schools adopt a growth or proficiency model, nor will it matter if they excel by either of those measures. They simply cannot afford to pursue education past high school.

We need a major redistribution of wealth from the richest Americans into the education system to fund public school districts, community colleges, and land-grant universities. Until then, we’re just replacing cogs in a broken machine.

To effectively oppose Trump and his cronies, our politics should be rooted in this line of attack. Trump ran on a pseudo-populist platform that promised to return working-class voters to the postwar boom years. Since the election, he’s packed his cabinet with billionaire hustlers, turned a make-work program into tax breaks for corporations, gone back on promises to preserve the remains of our welfare state, and used his presidency to increase bookings at his DC hotel.

He, his cabinet, and the Republicans are waging class warfare. If Democrats want oppose this agenda, they need to get on the battlefield.