There are a million flaws with the mainstream media, particularly cable news outlets, and we here at Paste delight in pointing them out as they occur. So it’s with a heavy heart that I must report the following: CNN has done a hell of a job with their single-issue 90-minute debate specials. They’re smart, they’re substantive, they’re necessary. Watch ten minutes of any of them, and you’ll learn more about how this country runs than you will watching 100 hours of superficial presidential debates. My guess is that these specials draw lower ratings than the normal talk shows CNN runs in primetime, so the network also deserves credit for airing them in the first place—it’s a terrific public service.

That said, they aren’t perfect. Many of the questions from the public, particularly from the conservative side, are set-ups with the usual “gotcha” formulations. In last night’s tax reform debate between Bernie Sanders and Ted Cruz, for instance, a small business owner with a soul patch took the microphone and brought up two separate facts:

1. Bernie Sanders called the current GOP tax reform plan “bad policy, disastrous, and morally repugnant.”

2. One part of the plan relates to small businesses.

If you’ve watched any of these debates, you can guess his question:

Why do you think small businesses are disastrous and morally repugnant?

This kind of thing is beneath intelligent discourse—obviously, when Sanders used those words, he was referring to the parts of the plan that benefit the super-wealthy while gutting Medicaid to pay for it, and wasn’t going out of his way to throw a zinger at small businessmen. Soul patch knew it, CNN knew it, and hopefully almost everyone watching knew it. But it’s a questioning technique CNN embraced during the presidential debates—against both sides, to be fair—and it doesn’t seem to be going away anytime soon.

That said, there were many more excellent questions than bad ones, and when a man named Jacob Kirkegaard from the Peterson Institute for International Economics took the mic, we were treated to one of the smartest questions I’ve ever seen in a televised debate. You can watch the exchange here:

This is about our priorities as Americans. All our people should get quality health care, higher education and child care. #CNNDebateNightpic.twitter.com/llDaT1Wp9u — Bernie Sanders (@SenSanders) October 19, 2017

Kirkegaard brought up a tough, but very fair, point—in order to institute government-funded social programs on a level akin to what we see in Scandinavian countries like Denmark, which Sanders often uses as a model of democratic-socialism, it’s not enough to simply hike taxes on the wealthy. For the kind of massive transformation that would give us universal health care, free public college tuition, daycare stipends, and etc., the middle class is also going to have to pay more in taxes. As Kirkegaard said, the requisite spending is simply too high.

“So while I’m very sympathetic to what you’re saying, my sense is still that you would like to spend as a Scandinavian but not tax as one, is that right?”

I’m an unrepentant Bernie Sanders fan, but I have to admit that on this issue, he was a bit cagy during the primary. In debates and interviews, he tended to dodge the idea in order to focus on the broader message of democratic-socialism. I can’t read his mind, but if I had my guess, he calculated (correctly) that America—shoved forcefully to the right by both parties for decades—could only digest so much “radical” information at one time, and it was enough, at that moment, to introduce the central concepts inherent to democratic-socialism without overwhelming his audience.

And he pulled off that feat with unprecedented success. When we talk about the “Overton Window” in America—defined as the “range of ideas tolerated in public discourse”—we find ourselves in a time where, at least on the center-left side of the scale, it is acceptable to talk about universal healthcare and use the word “socialism” in a positive context. That was not true a decade ago. It was not true five years ago. Frankly, it wasn’t true two years ago. It’s true now because of Bernie Sanders, who had the courage to use progressive rhetoric at a time when other Democrats wouldn’t dare. He shifted the Overton Window. Now, the Democrats have followed him, to the extent that anyone who dreams of running for president in 2020, including some dyed-in-the-wool centrists, have signed on to his universal healthcare bill in Congress.

All that said, he was not quite ready to make the final leap during the 2016 campaign and tell Americans that middle class taxes would also have to be raised. It’s an incredibly important idea, and an incendiary one. Due to the right-wing’s tight control of American discourse since at least 1980, we’ve been taught that taxes are inherently evil, and the majority of Americans have a viscerally negative reaction to the idea of raising them at all. (Even the idea of raising the taxes on the super-wealthy was seen as politically unfeasible for some centrist Democrats.)

Bottom line: In order to truly institute democratic-socialist programs, it will be necessary to shift the Overton Window even further, and make the case that higher taxes are actually good, that they will benefit society, and that they will save the middle class money on healthcare, education, and other costs in the final calculation.

Needless to say, this will be Sanders’ toughest act yet. He’s going against years of rhetorical dogma, and attempting to neuter one of the GOP’s bluntest weapons. He was not ready to fight that fight in 2016, even as he re-made our political reality.

And Jacob Kirkegaard called him out on it. That was important, but even more important? Sanders, for the first time that I can remember, admitted that he was right.

Granted, it was on a small stage, and granted, it will largely fly under the radar. Oh, and granted—he still didn’t say the words quite as overtly as he’ll eventually be forced to say them. But look at what he said to Kirkegaard after reviewing the cost of different services in Denmark:

And your point is well taken. To provide quality, virtually free childcare, to provide free higher education, to provide virtually free health care, it costs money. Nothing is free. Taxes are high. You’re right.

But I would suggest that the average American would rather pay $3,000 more in taxes and see a $5,000 premium to a private insurance company disappear. They will be better off….But to answer to your point, and it’s a fair point, nothing is for free. But I believe in a kind of society which is different from Ted’s does. I want to see all of our people — the young people, the old, the poor, the working class — be able to get the education they need, the health care they need, the job training they need. Does it cost money to do that? It does. But I believe, at the end of the day, that is the kind of nation that the American people would like to see us become.

Later, when Jake Tapper asked him if he thought Americans were ready to pay taxes like that, he went into a little more detail:

If we can have sensible discussions like this, yeah, I think they will be. Here is the point. If you’re an American watching this, listening to Senator Cruz say, oh, my god, Bernie Sanders want to raise my taxes.

But let me also tell you what he’s not telling you is that we’re going to do away with your private health insurance premium. Maybe you’re a family of four today on an individual insurance account and you’re paying $15,000, $20,000 for your family. And if I ended that private insurance that you’re paying to Blue Cross Blue Shield or some other private insurance company and said you’re going to pay $8,000 more in taxes, you’d be $12,000 to the good. And you and your kids would have comprehensive health care. So, yeah, you’re raising taxes, but you’re doing away with private insurance…

So, yes, to answer your question, Jake, if we can explain to people, yeah, you’re going to be paying more in taxes, it’s going to be a progressive tax system. The wealthy are going to pay their fair share, not the middle class, not the working class, but everybody will pay some more. But you’re going to get free health care and maybe you’re going to get free childcare, and maybe your kids are going to be able to go to college tuition-free, you know what, you’re going to be better off than under Ted’s system.

That is a statement of enormous importance. It re-frames the entire tax debate, just as Sanders re-framed the healthcare debate in 2016 and beyond. If America can be convinced that paying higher taxes is to their benefit, with the transformation of our social programs as an end goal, this is how it has to happen—with concrete, unapologetic arguments that demonstrate how Americans will benefit financially even as they pay more to the government. I may believe that higher taxes are a force of good, and other leftists may believe it, but there’s a ways to go before this idea can enter the mainstream.

Ted Cruz, a strong policy debater, did not miss the significance. Here’s what he said after the initial exchange between Sanders and Kirkegaard:

You know, we just witnessed a very important moment in this debate, which is that Bernie admitted that he wants to raise everyone’s taxes, not just the rich. The question was, to pay for this socialist state, you’ve got to raise everyone’s taxes, and Bernie said, yep, that’s right, your taxes are going up. That is a rare moment of candor in Washington.

And he’s right. But he also didn’t have a good argument against it. He tried to use the old attack line about how citizens in countries like Denmark have to wait months for hip replacements and other key surgeries (Sanders actually invited Kirkegaard back on stage to shoot that one down), and he dishonestly tried to compare Scandinavian nations to Cuba. In the end, when someone dared to state the unthinkable—that higher taxes are an agent of good—even Ted Cruz found himself at a loss.

It was an invigorating moment in American political discourse, even if it will largely go unnoticed for now. It’s also a necessary moment for those who believe in a progressive agenda. If someone like Sanders can overcome decades of propaganda—if he can not only say something that has been anathema for that long, but also make it resonate and get people to believe in it—it will be his greatest feat yet. And the dream of a democratic-socialist future in this country will be that much closer to reality.